diff --git a/EnvelopeGenerator.Infrastructure.Notification/EnvelopeNotificationService.cs b/EnvelopeGenerator.Infrastructure.Notification/EnvelopeNotificationService.cs
index 595caea0..4209a03c 100644
--- a/EnvelopeGenerator.Infrastructure.Notification/EnvelopeNotificationService.cs
+++ b/EnvelopeGenerator.Infrastructure.Notification/EnvelopeNotificationService.cs
@@ -1,9 +1,6 @@
 using DigitalData.Core.Abstraction.Application.Repository;
-using DigitalData.MessagingService.Application.Common.Dto;
 using DigitalData.MessagingService.Application.Common.Interfaces;
 using DigitalData.MessagingService.Application.EmailSending.Commands;
-using DigitalData.MessagingService.Client;
-using DigitalData.MessagingService.Domain.Entities;
 using EnvelopeGenerator.Application.Common.Interfaces.Services.Notification;
 using EnvelopeGenerator.Domain.Constants;
 using EnvelopeGenerator.Domain.Entities;
diff --git a/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Components/Sender/CreateEnvelopeWizardPopup.razor b/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Components/Sender/CreateEnvelopeWizardPopup.razor
index 2d86320e..bab1bd41 100644
--- a/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Components/Sender/CreateEnvelopeWizardPopup.razor
+++ b/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Components/Sender/CreateEnvelopeWizardPopup.razor
@@ -5,6 +5,7 @@
 @using EnvelopeGenerator.Domain.Resources
 @using EnvelopeGenerator.Server.Client.Components.Sender.ReceiverSuggestionFilter
 @using EnvelopeGenerator.Server.Client.Services
+@using MudBlazor
 @using Microsoft.AspNetCore.Components.Forms
 @using Microsoft.Extensions.Localization
 @inject IStringLocalizer<Model> ModelLocalizer
@@ -27,333 +28,341 @@
         <div class="sender-create-wizard"
              tabindex="0"
              @onkeydown="OnWizardKeyDownAsync">
-            <div class="sender-create-wizard__progress">
-                <div class="sender-create-wizard__progress-track"></div>
-                @for (var step = 0; step < TotalSteps; step++)
-                {
-                    var isActive = step == _currentStep;
-                    var isDone = step < _currentStep;
-                    <div class="sender-create-wizard__step @(isActive ? "sender-create-wizard__step--active" : string.Empty) @(isDone ? "sender-create-wizard__step--done" : string.Empty)">
-                        <span class="sender-create-wizard__step-index">@(step + 1)</span>
-                    </div>
-                }
-            </div>
+            <MudPaper Class="sender-create-wizard__stepper-shell" Elevation="0">
+                <MudStepper Vertical="true"
+                            NonLinear="false"
+                            ShowResetButton="false"
+                            ActiveIndex="@_currentStep"
+                            Class="sender-create-wizard__stepper">
+                    <ChildContent>
+                        @for (var step = 0; step < TotalSteps; step++)
+                        {
+                            var stepIndex = step;
 
-            <div class="sender-create-wizard__meta">
-                <div class="sender-create-wizard__title">@CurrentStepTitle</div>
-                <div class="sender-create-wizard__description">@CurrentStepDescription</div>
-            </div>
+                            <MudStep Title="@GetStepTitle(stepIndex)">
+                                <div class="sender-create-wizard__stepper-description">@GetStepDescription(stepIndex)</div>
+
+                                @if (stepIndex == _currentStep)
+                                {
+                                    <div class="sender-create-wizard__step-content">
+                                        @if (_currentStep == 0)
+                                        {
+                                            <div class="sender-create-wizard__form-grid">
+                                                <div class="sender-create-wizard__field">
+                                                    <label class="sender-create-wizard__label">
+                                                        @L("Title", "Titel") <span class="sender-create-wizard__required">*</span>
+                                                    </label>
+                                                    <DxTextBox Text="@_title"
+                                                               TextChanged="OnTitleChanged"
+                                                               BindValueMode="BindValueMode.OnInput"
+                                                               NullText='@L("SenderEditor_Title_Placeholder", "z.B. Arbeitsvertrag 2025")'
+                                                               CssClass="w-100" />
+                                                </div>
+
+                                                <div class="sender-create-wizard__field">
+                                                    <label class="sender-create-wizard__label">
+                                                        @L("EnvelopeType", "Umschlagtyp") <span class="sender-create-wizard__required">*</span>
+                                                    </label>
+                                                    <select value="@(_selectedEnvelopeTypeId?.ToString() ?? string.Empty)"
+                                                            @onchange="OnEnvelopeTypeChanged"
+                                                            class="sender-create-wizard__select">
+                                                        @foreach (var type in EnvelopeTypes)
+                                                        {
+                                                            <option value="@type.Id">@type.Title</option>
+                                                        }
+                                                    </select>
+                                                </div>
+                                            </div>
+                                        }
+                                        else if (_currentStep == 1)
+                                        {
+                                            <div class="sender-create-wizard__form-grid">
+                                                <div class="sender-create-wizard__field sender-create-wizard__field--full">
+                                                    <label class="sender-create-wizard__label">
+                                                        @L("Message", "Nachricht") <span class="sender-create-wizard__optional">(@L("Optional", "optional"))</span>
+                                                    </label>
+                                                    <DxMemo Text="@_message"
+                                                            TextChanged="OnMessageChanged"
+                                                            Rows="5"
+                                                            MaxLength="500"
+                                                            NullText='@L("SenderEditor_Message_Placeholder", "Bitte unterzeichnen Sie das beigefügte Dokument.")'
+                                                            CssClass="w-100" />
+                                                </div>
+
+                                                <div class="sender-create-wizard__field">
+                                                    <label class="sender-create-wizard__label">
+                                                        @L("Language", "Sprache")
+                                                    </label>
+                                                    <select @bind="_language" class="sender-create-wizard__select">
+                                                        <option value="de-DE">Deutsch (de-DE)</option>
+                                                        <option value="en-US">English (en-US)</option>
+                                                        <option value="de">Deutsch (de)</option>
+                                                        <option value="en">English (en)</option>
+                                                    </select>
+                                                </div>
+                                            </div>
+                                        }
+                                        else if (_currentStep == 2)
+                                        {
+                                            <div class="sender-create-wizard__settings-grid">
+                                                <div class="sender-create-wizard__settings-group">
+                                                    <div class="sender-create-wizard__settings-title">
+                                                        @L("SenderEditor_EnvelopeSettings", "Envelope-Einstellungen")
+                                                    </div>
+
+                                                    <div class="sender-create-wizard__form-grid">
+                                                        <div class="sender-create-wizard__field">
+                                                            <label class="sender-create-wizard__label">@L("CertificationType", "Zertifizierung")</label>
+                                                            <select @bind="_certificationType" class="sender-create-wizard__select">
+                                                                <option value="@CertificationType.AdvancedElectronicSignature">@L("AdvancedElectronicSignature", "Advanced Electronic Signature")</option>
+                                                                <option value="@CertificationType.ElectronicSignature">@L("ElectronicSignature", "Electronic Signature")</option>
+                                                            </select>
+                                                        </div>
+
+                                                        <div class="sender-create-wizard__field">
+                                                            <label class="sender-create-wizard__label">@L("FinalEmailToCreator", "Finale E-Mail an Ersteller")</label>
+                                                            <select @bind="_finalEmailToCreator" class="sender-create-wizard__select">
+                                                                <option value="0">@L("No", "Nein")</option>
+                                                                <option value="1">@L("Yes", "Ja")</option>
+                                                                <option value="2">@L("YesWithAttachment", "Ja, mit Anhang")</option>
+                                                            </select>
+                                                        </div>
+
+                                                        <div class="sender-create-wizard__field">
+                                                            <label class="sender-create-wizard__label">@L("FinalEmailToReceivers", "Finale E-Mail an Empfänger")</label>
+                                                            <select @bind="_finalEmailToReceivers" class="sender-create-wizard__select">
+                                                                <option value="0">@L("No", "Nein")</option>
+                                                                <option value="1">@L("Yes", "Ja")</option>
+                                                                <option value="2">@L("YesWithAttachment", "Ja, mit Anhang")</option>
+                                                            </select>
+                                                        </div>
+
+                                                        <div class="sender-create-wizard__field sender-create-wizard__field--full">
+                                                            <div class="sender-create-wizard__settings-toggles">
+                                                                <label class="sender-create-wizard__settings-toggle">
+                                                                    <input type="checkbox" checked="@_tfaEnabled" @onchange="OnTfaChanged" />
+                                                                    @L("TFAEnabled", "2FA aktiviert")
+                                                                </label>
+                                                                <label class="sender-create-wizard__settings-toggle">
+                                                                    <input type="checkbox" checked="@_useAccessCode" @onchange="OnUseAccessCodeChanged" disabled="@_tfaEnabled" />
+                                                                    @L("UseAccessCode", "Zugriffscode verwenden")
+                                                                </label>
+                                                            </div>
+                                                        </div>
+                                                    </div>
+                                                </div>
+
+                                                <div class="sender-create-wizard__settings-group">
+                                                    <div class="sender-create-wizard__settings-title">
+                                                        @L("SendReminderEmails", "Erinnerungs-E-Mails senden")
+                                                    </div>
+
+                                                    <div class="sender-create-wizard__form-grid">
+                                                        <div class="sender-create-wizard__field sender-create-wizard__field--full">
+                                                            <label class="sender-create-wizard__settings-toggle">
+                                                                <input type="checkbox" checked="@_sendReminderEmails" @onchange="OnSendReminderEmailsChanged" />
+                                                                @L("SendReminderEmails", "Erinnerungs-E-Mails senden")
+                                                            </label>
+                                                        </div>
+
+                                                        <div class="sender-create-wizard__field">
+                                                            <label class="sender-create-wizard__label">@L("FirstReminderDays", "Erste Erinnerung (Tage)")</label>
+                                                            <InputNumber @bind-Value="_firstReminderDays" class="form-control form-control-sm" disabled="@(!_sendReminderEmails)" />
+                                                        </div>
+
+                                                        <div class="sender-create-wizard__field">
+                                                            <label class="sender-create-wizard__label">@L("ReminderIntervalDays", "Erinnerungsintervall (Tage)")</label>
+                                                            <InputNumber @bind-Value="_reminderIntervalDays" class="form-control form-control-sm" disabled="@(!_sendReminderEmails)" />
+                                                        </div>
+
+                                                        <div class="sender-create-wizard__field">
+                                                            <label class="sender-create-wizard__label">@L("ExpiresWhenDays", "Läuft ab nach (Tage)")</label>
+                                                            <InputNumber @bind-Value="_expiresWhenDays" class="form-control form-control-sm" />
+                                                        </div>
+
+                                                        <div class="sender-create-wizard__field">
+                                                            <label class="sender-create-wizard__label">@L("ExpiresWarningWhenDays", "Ablaufwarnung (Tage)")</label>
+                                                            <InputNumber @bind-Value="_expiresWarningWhenDays" class="form-control form-control-sm" />
+                                                        </div>
+                                                    </div>
+                                                </div>
+                                            </div>
+                                        }
+                                        else if (_currentStep == 3)
+                                        {
+                                            <div class="sender-create-wizard__suggestions">
+                                                <div class="sender-create-wizard__suggestions-title">@L("SenderWizard_RecentReceivers", "Zuletzt verwendete Empfänger")</div>
+
+                                                @if (_isLoadingRecentSuggestions)
+                                                {
+                                                    <div class="sender-create-wizard__empty-list">@L("Loading", "Lädt...")</div>
+                                                }
+                                                else if (_recentReceiverSuggestions.Count > 0)
+                                                {
+                                                    <div class="sender-create-wizard__suggestion-list" role="listbox" aria-label="Recent receivers">
+                                                        @foreach (var suggestion in FilteredRecentSuggestions)
+                                                        {
+                                                            <button type="button"
+                                                                    class="sender-create-wizard__suggestion-item"
+                                                                    @onclick="() => ApplyRecentSuggestion(suggestion)"
+                                                                    disabled="@IsActionLocked">
+                                                                <span class="sender-create-wizard__suggestion-name">@suggestion.FullName</span>
+                                                                <span class="sender-create-wizard__suggestion-email">@suggestion.EmailAddress</span>
+                                                            </button>
+                                                        }
+                                                    </div>
+                                                }
+                                            </div>
+
+                                            <div class="sender-create-wizard__form-grid">
+                                                <div class="sender-create-wizard__field">
+                                                    <label class="sender-create-wizard__label">
+                                                        @L("FullName", "Vor- und Nachname") <span class="sender-create-wizard__required">*</span>
+                                                    </label>
+                                                    <DxTextBox Text="@_receiverName"
+                                                               TextChanged="OnReceiverNameChanged"
+                                                               BindValueMode="BindValueMode.OnInput"
+                                                               NullText="Max Mustermann"
+                                                               CssClass="w-100" />
+                                                </div>
+
+                                                <div class="sender-create-wizard__field">
+                                                    <label class="sender-create-wizard__label">
+                                                        @L("EmailAddress", "E-Mail-Adresse") <span class="sender-create-wizard__required">*</span>
+                                                    </label>
+                                                    <DxTextBox Text="@_receiverEmail"
+                                                               TextChanged="OnReceiverEmailChanged"
+                                                               BindValueMode="BindValueMode.OnInput"
+                                                               NullText="name@beispiel.de"
+                                                               CssClass="w-100" />
+                                                </div>
+                                            </div>
+
+                                            <div class="sender-create-wizard__receiver-actions">
+                                                <button type="button"
+                                                        class="sender-create-wizard__add-receiver-btn"
+                                                        @onclick="AddReceiver"
+                                                        disabled="@IsActionLocked">
+                                                    <svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" fill="currentColor" viewBox="0 0 16 16" aria-hidden="true">
+                                                        <path d="M8 4a.5.5 0 0 1 .5.5V7.5H11.5a.5.5 0 0 1 0 1H8.5v3a.5.5 0 0 1-1 0v-3H4.5a.5.5 0 0 1 0-1H7.5v-3A.5.5 0 0 1 8 4z" />
+                                                    </svg>
+                                                    <span>@L("AddReceiver", "Empfänger hinzufügen")</span>
+                                                </button>
+                                            </div>
+
+                                            @if (_receivers.Count == 0)
+                                            {
+                                                <div class="sender-create-wizard__empty-list">
+                                                    @L("SenderEditor_NoReceiversAdded", "Noch keine Empfänger hinzugefügt.")
+                                                </div>
+                                            }
+                                            else
+                                            {
+                                                <div class="sender-create-wizard__receiver-tagbox-wrap">
+                                                    <label class="sender-create-wizard__label" for="wizardReceiversTagBox">
+                                                        @L("Receiver", "Empfänger")
+                                                    </label>
+                                                    <DxTagBox Data="@_receivers"
+                                                              TData="CreateEnvelopeWizardReceiver"
+                                                              TValue="CreateEnvelopeWizardReceiver"
+                                                              AllowCustomTags="true"
+                                                              @bind-Tags="@_receiverTags"
+                                                              @bind-Tags:after="OnReceiverTagsChanged"
+                                                              HideSelectedItems="false"
+                                                              TextFieldName="@nameof(CreateEnvelopeWizardReceiver.EmailAddress)"
+                                                              ListRenderMode="ListRenderMode.Virtual"
+                                                              SearchMode="ListSearchMode.AutoSearch"
+                                                              SearchFilterCondition="ListSearchFilterCondition.Contains"
+                                                              SearchTextParseMode="ListSearchTextParseMode.GroupWordsByAnd"
+                                                              CssClass="sender-create-wizard__receiver-tagbox"
+                                                              InputId="wizardReceiversTagBox"
+                                                              Enabled="@(!IsActionLocked)">
+                                                        <TagDisplayTemplate Context="tagContext">
+                                                            <div class="sender-create-wizard__receiver-tag">
+                                                                @if (tagContext.DataItem is CreateEnvelopeWizardReceiver receiver)
+                                                                {
+                                                                    <span class="sender-create-wizard__receiver-tag-name">@receiver.FullName</span>
+                                                                    <span class="sender-create-wizard__receiver-tag-email">@receiver.EmailAddress</span>
+                                                                }
+                                                                else
+                                                                {
+                                                                    <span class="sender-create-wizard__receiver-tag-email">@tagContext.DisplayText</span>
+                                                                }
+                                                                <button type="button"
+                                                                        class="sender-create-wizard__receiver-tag-remove"
+                                                                        @onclick="tagContext.RemoveTagAction"
+                                                                        aria-label="Remove receiver"
+                                                                        disabled="@IsActionLocked">x</button>
+                                                            </div>
+                                                        </TagDisplayTemplate>
+                                                        <EmptyDataAreaTemplate Context="emptyContext">
+                                                            <div class="sender-create-wizard__tagbox-empty"></div>
+                                                        </EmptyDataAreaTemplate>
+                                                    </DxTagBox>
+                                                </div>
+                                            }
+                                        }
+                                        else
+                                        {
+                                            <div class="sender-create-wizard__upload-stage">
+                                                <label class="sender-create-wizard__upload-btn @(IsActionLocked ? "sender-create-wizard__upload-btn--disabled" : string.Empty)">
+                                                    @if (_documentBytes is null)
+                                                    {
+                                                        <span>@L("UploadPdf", "PDF hochladen")</span>
+                                                    }
+                                                    else
+                                                    {
+                                                        <span>@L("SenderWizard_ReplacePdf", "PDF ersetzen")</span>
+                                                    }
+                                                    <InputFile OnChange="OnDocumentSelectedAsync"
+                                                               accept=".pdf"
+                                                               disabled="@IsActionLocked"
+                                                               class="sender-create-wizard__hidden-input" />
+                                                </label>
+
+                                                @if (_documentBytes is not null)
+                                                {
+                                                    <div class="sender-create-wizard__document-preview-card">
+                                                        <div class="sender-create-wizard__document-meta">
+                                                            <div class="sender-create-wizard__document-name">@_documentFileName</div>
+                                                            <div class="sender-create-wizard__document-size">@_documentSizeText</div>
+                                                        </div>
+                                                        <div class="sender-create-wizard__document-preview-wrap">
+                                                            <SenderPdfImageEditor IsPlacementMode="false"
+                                                                                  PageCount="@_documentPreviewPageCount"
+                                                                                  Pages="@_documentPreviewPages"
+                                                                                  PdfDataUrl="@DocumentPreviewDataUrl"
+                                                                                  PdfFileName="@_documentFileName"
+                                                                                  Fields="@_documentPreviewFieldOverlays"
+                                                                                  EditorClick="OnDocumentPreviewEditorClickAsync"
+                                                                                  RemoveField="OnDocumentPreviewRemoveFieldAsync"
+                                                                                  MoveField="OnDocumentPreviewMoveFieldAsync" />
+                                                        </div>
+                                                    </div>
+                                                }
+                                                else
+                                                {
+                                                    <PdfFileDropZone Disabled="@IsActionLocked"
+                                                                     HasDocument="false"
+                                                                     UploadText='@L("SenderWizard_DocumentRequiredHint", "Bitte laden Sie ein PDF-Dokument hoch, um fortzufahren.")'
+                                                                     DragDropHintText='@L("SenderWizard_DragDropPdfHint", "Oder ziehen Sie die PDF-Datei hierher.")'
+                                                                     FileSelected="OnDocumentSelectedAsync" />
+                                                }
+                                            </div>
+                                        }
+                                    </div>
+                                }
+                            </MudStep>
+                        }
+                    </ChildContent>
+                </MudStepper>
+            </MudPaper>
 
             @if (!string.IsNullOrWhiteSpace(_validationMessage))
             {
                 <div class="sender-create-wizard__validation">@_validationMessage</div>
             }
 
-            @if (_currentStep == 0)
-            {
-                <div class="sender-create-wizard__form-grid">
-                    <div class="sender-create-wizard__field">
-                        <label class="sender-create-wizard__label">
-                            @L("Title", "Titel") <span class="sender-create-wizard__required">*</span>
-                        </label>
-                        <DxTextBox Text="@_title"
-                                   TextChanged="OnTitleChanged"
-                                   BindValueMode="BindValueMode.OnInput"
-                                   NullText='@L("SenderEditor_Title_Placeholder", "z.B. Arbeitsvertrag 2025")'
-                                   CssClass="w-100" />
-                    </div>
-
-                    <div class="sender-create-wizard__field">
-                        <label class="sender-create-wizard__label">
-                            @L("EnvelopeType", "Umschlagtyp") <span class="sender-create-wizard__required">*</span>
-                        </label>
-                        <select value="@(_selectedEnvelopeTypeId?.ToString() ?? string.Empty)"
-                                @onchange="OnEnvelopeTypeChanged"
-                                class="sender-create-wizard__select">
-                            @foreach (var type in EnvelopeTypes)
-                            {
-                                <option value="@type.Id">@type.Title</option>
-                            }
-                        </select>
-                    </div>
-                </div>
-            }
-            else if (_currentStep == 1)
-            {
-                <div class="sender-create-wizard__form-grid">
-                    <div class="sender-create-wizard__field sender-create-wizard__field--full">
-                        <label class="sender-create-wizard__label">
-                            @L("Message", "Nachricht") <span class="sender-create-wizard__optional">(@L("Optional", "optional"))</span>
-                        </label>
-                        <DxMemo Text="@_message"
-                                TextChanged="OnMessageChanged"
-                                Rows="5"
-                                MaxLength="500"
-                                NullText='@L("SenderEditor_Message_Placeholder", "Bitte unterzeichnen Sie das beigefügte Dokument.")'
-                                CssClass="w-100" />
-                    </div>
-
-                    <div class="sender-create-wizard__field">
-                        <label class="sender-create-wizard__label">
-                            @L("Language", "Sprache")
-                        </label>
-                        <select @bind="_language" class="sender-create-wizard__select">
-                            <option value="de-DE">Deutsch (de-DE)</option>
-                            <option value="en-US">English (en-US)</option>
-                            <option value="de">Deutsch (de)</option>
-                            <option value="en">English (en)</option>
-                        </select>
-                    </div>
-                </div>
-            }
-            else if (_currentStep == 2)
-            {
-                <div class="sender-create-wizard__settings-grid">
-                    <div class="sender-create-wizard__settings-group">
-                        <div class="sender-create-wizard__settings-title">
-                            @L("SenderEditor_EnvelopeSettings", "Envelope-Einstellungen")
-                        </div>
-
-                        <div class="sender-create-wizard__form-grid">
-                            <div class="sender-create-wizard__field">
-                                <label class="sender-create-wizard__label">@L("CertificationType", "Zertifizierung")</label>
-                                <select @bind="_certificationType" class="sender-create-wizard__select">
-                                    <option value="@CertificationType.AdvancedElectronicSignature">@L("AdvancedElectronicSignature", "Advanced Electronic Signature")</option>
-                                    <option value="@CertificationType.ElectronicSignature">@L("ElectronicSignature", "Electronic Signature")</option>
-                                </select>
-                            </div>
-
-                            <div class="sender-create-wizard__field">
-                                <label class="sender-create-wizard__label">@L("FinalEmailToCreator", "Finale E-Mail an Ersteller")</label>
-                                <select @bind="_finalEmailToCreator" class="sender-create-wizard__select">
-                                    <option value="0">@L("No", "Nein")</option>
-                                    <option value="1">@L("Yes", "Ja")</option>
-                                    <option value="2">@L("YesWithAttachment", "Ja, mit Anhang")</option>
-                                </select>
-                            </div>
-
-                            <div class="sender-create-wizard__field">
-                                <label class="sender-create-wizard__label">@L("FinalEmailToReceivers", "Finale E-Mail an Empfänger")</label>
-                                <select @bind="_finalEmailToReceivers" class="sender-create-wizard__select">
-                                    <option value="0">@L("No", "Nein")</option>
-                                    <option value="1">@L("Yes", "Ja")</option>
-                                    <option value="2">@L("YesWithAttachment", "Ja, mit Anhang")</option>
-                                </select>
-                            </div>
-
-                            <div class="sender-create-wizard__field sender-create-wizard__field--full">
-                                <div class="sender-create-wizard__settings-toggles">
-                                    <label class="sender-create-wizard__settings-toggle">
-                                        <input type="checkbox" checked="@_tfaEnabled" @onchange="OnTfaChanged" />
-                                        @L("TFAEnabled", "2FA aktiviert")
-                                    </label>
-                                    <label class="sender-create-wizard__settings-toggle">
-                                        <input type="checkbox" checked="@_useAccessCode" @onchange="OnUseAccessCodeChanged" disabled="@_tfaEnabled" />
-                                        @L("UseAccessCode", "Zugriffscode verwenden")
-                                    </label>
-                                </div>
-                            </div>
-                        </div>
-                    </div>
-
-                    <div class="sender-create-wizard__settings-group">
-                        <div class="sender-create-wizard__settings-title">
-                            @L("SendReminderEmails", "Erinnerungs-E-Mails senden")
-                        </div>
-
-                        <div class="sender-create-wizard__form-grid">
-                            <div class="sender-create-wizard__field sender-create-wizard__field--full">
-                                <label class="sender-create-wizard__settings-toggle">
-                                    <input type="checkbox" checked="@_sendReminderEmails" @onchange="OnSendReminderEmailsChanged" />
-                                    @L("SendReminderEmails", "Erinnerungs-E-Mails senden")
-                                </label>
-                            </div>
-
-                            <div class="sender-create-wizard__field">
-                                <label class="sender-create-wizard__label">@L("FirstReminderDays", "Erste Erinnerung (Tage)")</label>
-                                <InputNumber @bind-Value="_firstReminderDays" class="form-control form-control-sm" disabled="@(!_sendReminderEmails)" />
-                            </div>
-
-                            <div class="sender-create-wizard__field">
-                                <label class="sender-create-wizard__label">@L("ReminderIntervalDays", "Erinnerungsintervall (Tage)")</label>
-                                <InputNumber @bind-Value="_reminderIntervalDays" class="form-control form-control-sm" disabled="@(!_sendReminderEmails)" />
-                            </div>
-
-                            <div class="sender-create-wizard__field">
-                                <label class="sender-create-wizard__label">@L("ExpiresWhenDays", "Läuft ab nach (Tage)")</label>
-                                <InputNumber @bind-Value="_expiresWhenDays" class="form-control form-control-sm" />
-                            </div>
-
-                            <div class="sender-create-wizard__field">
-                                <label class="sender-create-wizard__label">@L("ExpiresWarningWhenDays", "Ablaufwarnung (Tage)")</label>
-                                <InputNumber @bind-Value="_expiresWarningWhenDays" class="form-control form-control-sm" />
-                            </div>
-                        </div>
-                    </div>
-                </div>
-            }
-            else if (_currentStep == 3)
-            {
-                <div class="sender-create-wizard__suggestions">
-                    <div class="sender-create-wizard__suggestions-title">@L("SenderWizard_RecentReceivers", "Zuletzt verwendete Empfänger")</div>
-
-                    @if (_isLoadingRecentSuggestions)
-                    {
-                        <div class="sender-create-wizard__empty-list">@L("Loading", "Lädt...")</div>
-                    }
-                    else if (_recentReceiverSuggestions.Count > 0)
-                    {
-                        <div class="sender-create-wizard__suggestion-list" role="listbox" aria-label="Recent receivers">
-                            @foreach (var suggestion in FilteredRecentSuggestions)
-                            {
-                                <button type="button"
-                                        class="sender-create-wizard__suggestion-item"
-                                        @onclick="() => ApplyRecentSuggestion(suggestion)"
-                                        disabled="@IsActionLocked">
-                                    <span class="sender-create-wizard__suggestion-name">@suggestion.FullName</span>
-                                    <span class="sender-create-wizard__suggestion-email">@suggestion.EmailAddress</span>
-                                </button>
-                            }
-                        </div>
-                    }
-                </div>
-
-                <div class="sender-create-wizard__form-grid">
-                    <div class="sender-create-wizard__field">
-                        <label class="sender-create-wizard__label">
-                            @L("FullName", "Vor- und Nachname") <span class="sender-create-wizard__required">*</span>
-                        </label>
-                        <DxTextBox Text="@_receiverName"
-                                   TextChanged="OnReceiverNameChanged"
-                                   BindValueMode="BindValueMode.OnInput"
-                                   NullText="Max Mustermann"
-                                   CssClass="w-100" />
-                    </div>
-
-                    <div class="sender-create-wizard__field">
-                        <label class="sender-create-wizard__label">
-                            @L("EmailAddress", "E-Mail-Adresse") <span class="sender-create-wizard__required">*</span>
-                        </label>
-                        <DxTextBox Text="@_receiverEmail"
-                                   TextChanged="OnReceiverEmailChanged"
-                                   BindValueMode="BindValueMode.OnInput"
-                                   NullText="name@beispiel.de"
-                                   CssClass="w-100" />
-                    </div>
-                </div>
-
-                <div class="sender-create-wizard__receiver-actions">
-                    <button type="button"
-                            class="sender-create-wizard__add-receiver-btn"
-                            @onclick="AddReceiver"
-                            disabled="@IsActionLocked">
-                        <svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" fill="currentColor" viewBox="0 0 16 16" aria-hidden="true">
-                            <path d="M8 4a.5.5 0 0 1 .5.5V7.5H11.5a.5.5 0 0 1 0 1H8.5v3a.5.5 0 0 1-1 0v-3H4.5a.5.5 0 0 1 0-1H7.5v-3A.5.5 0 0 1 8 4z" />
-                        </svg>
-                        <span>@L("AddReceiver", "Empfänger hinzufügen")</span>
-                    </button>
-                </div>
-
-                @if (_receivers.Count == 0)
-                {
-                    <div class="sender-create-wizard__empty-list">
-                        @L("SenderEditor_NoReceiversAdded", "Noch keine Empfänger hinzugefügt.")
-                    </div>
-                }
-                else
-                {
-                    <div class="sender-create-wizard__receiver-tagbox-wrap">
-                        <label class="sender-create-wizard__label" for="wizardReceiversTagBox">
-                            @L("Receiver", "Empfänger")
-                        </label>
-                        <DxTagBox Data="@_receivers"
-                                  TData="CreateEnvelopeWizardReceiver"
-                                  TValue="CreateEnvelopeWizardReceiver"
-                                  AllowCustomTags="true"
-                                  @bind-Tags="@_receiverTags"
-                                  @bind-Tags:after="OnReceiverTagsChanged"
-                                  HideSelectedItems="false"
-                                  TextFieldName="@nameof(CreateEnvelopeWizardReceiver.EmailAddress)"
-                                  ListRenderMode="ListRenderMode.Virtual"
-                                  SearchMode="ListSearchMode.AutoSearch"
-                                  SearchFilterCondition="ListSearchFilterCondition.Contains"
-                                  SearchTextParseMode="ListSearchTextParseMode.GroupWordsByAnd"
-                                  CssClass="sender-create-wizard__receiver-tagbox"
-                                  InputId="wizardReceiversTagBox"
-                                  Enabled="@(!IsActionLocked)">
-                            <TagDisplayTemplate Context="tagContext">
-                                <div class="sender-create-wizard__receiver-tag">
-                                    @if (tagContext.DataItem is CreateEnvelopeWizardReceiver receiver)
-                                    {
-                                        <span class="sender-create-wizard__receiver-tag-name">@receiver.FullName</span>
-                                        <span class="sender-create-wizard__receiver-tag-email">@receiver.EmailAddress</span>
-                                    }
-                                    else
-                                    {
-                                        <span class="sender-create-wizard__receiver-tag-email">@tagContext.DisplayText</span>
-                                    }
-                                    <button type="button"
-                                            class="sender-create-wizard__receiver-tag-remove"
-                                            @onclick="tagContext.RemoveTagAction"
-                                            aria-label="Remove receiver"
-                                            disabled="@IsActionLocked">x</button>
-                                </div>
-                            </TagDisplayTemplate>
-                            <EmptyDataAreaTemplate Context="emptyContext">
-                                <div class="sender-create-wizard__tagbox-empty"></div>
-                            </EmptyDataAreaTemplate>
-                        </DxTagBox>
-                    </div>
-                }
-            }
-            else
-            {
-                <div class="sender-create-wizard__upload-stage">
-                    <label class="sender-create-wizard__upload-btn @(IsActionLocked ? "sender-create-wizard__upload-btn--disabled" : string.Empty)">
-                        @if (_documentBytes is null)
-                        {
-                            <span>@L("UploadPdf", "PDF hochladen")</span>
-                        }
-                        else
-                        {
-                            <span>@L("SenderWizard_ReplacePdf", "PDF ersetzen")</span>
-                        }
-                        <InputFile OnChange="OnDocumentSelectedAsync"
-                                   accept=".pdf"
-                                   disabled="@IsActionLocked"
-                                   class="sender-create-wizard__hidden-input" />
-                    </label>
-
-                    @if (_documentBytes is not null)
-                    {
-                        <div class="sender-create-wizard__document-preview-card">
-                            <div class="sender-create-wizard__document-meta">
-                                <div class="sender-create-wizard__document-name">@_documentFileName</div>
-                                <div class="sender-create-wizard__document-size">@_documentSizeText</div>
-                            </div>
-                            <div class="sender-create-wizard__document-preview-wrap">
-                                <SenderPdfImageEditor IsPlacementMode="false"
-                                                      PageCount="@_documentPreviewPageCount"
-                                                      Pages="@_documentPreviewPages"
-                                                      PdfDataUrl="@DocumentPreviewDataUrl"
-                                                      PdfFileName="@_documentFileName"
-                                                      Fields="@_documentPreviewFieldOverlays"
-                                                      EditorClick="OnDocumentPreviewEditorClickAsync"
-                                                      RemoveField="OnDocumentPreviewRemoveFieldAsync"
-                                                      MoveField="OnDocumentPreviewMoveFieldAsync" />
-                            </div>
-                        </div>
-                    }
-                    else
-                    {
-                        <PdfFileDropZone Disabled="@IsActionLocked"
-                                         HasDocument="false"
-                                         UploadText='@L("SenderWizard_DocumentRequiredHint", "Bitte laden Sie ein PDF-Dokument hoch, um fortzufahren.")'
-                                         DragDropHintText='@L("SenderWizard_DragDropPdfHint", "Oder ziehen Sie die PDF-Datei hierher.")'
-                                         FileSelected="OnDocumentSelectedAsync" />
-                    }
-                </div>
-            }
         </div>
     </BodyContentTemplate>
     <FooterContentTemplate>
@@ -465,7 +474,11 @@
         ? $"data:application/pdf;base64,{Convert.ToBase64String(_documentBytes)}"
         : null;
 
-    private string CurrentStepTitle => _currentStep switch
+    private string CurrentStepTitle => GetStepTitle(_currentStep);
+
+    private string CurrentStepDescription => GetStepDescription(_currentStep);
+
+    private string GetStepTitle(int step) => step switch
     {
         0 => L("SenderWizard_Step_Basics", "Grunddaten"),
         1 => L("SenderWizard_Step_Message", "Nachricht und Optionen"),
@@ -475,7 +488,7 @@
         _ => L("SenderWizard_Step_Basics", "Grunddaten")
     };
 
-    private string CurrentStepDescription => _currentStep switch
+    private string GetStepDescription(int step) => step switch
     {
         0 => L("SenderWizard_Step_Basics_Desc", "Starten Sie mit den Pflichtangaben für den Umschlag."),
         1 => L("SenderWizard_Step_Message_Desc", "Fügen Sie optionale Nachricht und Einstellungen hinzu."),
diff --git a/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/EnvelopeGenerator.Server.Client.csproj b/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/EnvelopeGenerator.Server.Client.csproj
index b00ba988..79d4555f 100644
--- a/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/EnvelopeGenerator.Server.Client.csproj
+++ b/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/EnvelopeGenerator.Server.Client.csproj
@@ -12,6 +12,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="MudBlazor" Version="8.0.0" />
     <PackageReference Include="DevExpress.Blazor.PdfViewer" Version="25.2.3" />
     <PackageReference Include="DevExpress.Blazor.Reporting.JSBasedControls" Version="25.2.3" />
     <PackageReference Include="DevExpress.Blazor.Reporting.Viewer" Version="25.2.3" />
diff --git a/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Program.cs b/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Program.cs
index 24e5a89d..46c37a95 100644
--- a/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Program.cs
+++ b/EnvelopeGenerator.Server/EnvelopeGenerator.Server.Client/Program.cs
@@ -1,6 +1,7 @@
 using Microsoft.AspNetCore.Components.WebAssembly.Hosting;
 using EnvelopeGenerator.Server.Client.Services;
 using EnvelopeGenerator.Server.Client.Options;
+using MudBlazor.Services;
 using DevExpress.Blazor.Reporting;
 using DevExpress.XtraReports.Web.Extensions;
 using DevExpress.DataAccess.Web;
@@ -16,6 +17,7 @@ CultureInfo.DefaultThreadCurrentCulture = cultureInfo;
 CultureInfo.DefaultThreadCurrentUICulture = cultureInfo;
 
 builder.Services.AddLocalization();
+builder.Services.AddMudServices();
 
 // Named HttpClient for API calls (both for services and DevExpress components)
 builder.Services.AddHttpClient("EnvelopeGenerator.Server", client =>
diff --git a/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Components/App.razor b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Components/App.razor
index 6d5ebdc4..24351640 100644
--- a/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Components/App.razor
+++ b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Components/App.razor
@@ -9,6 +9,7 @@
     <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/flag-icons@7.2.3/css/flag-icons.min.css" />
     <link rel="stylesheet" href="css/app.css" />
     <link rel="stylesheet" href="css/envelope-viewer.css" />
+    <link rel="stylesheet" href="_content/MudBlazor/MudBlazor.min.css" />
     <link rel="stylesheet" href="EnvelopeGenerator.Server.styles.css" />
     <HeadOutlet />
     <!-- Apply saved theme immediately on page load — before WASM boots.
@@ -37,6 +38,7 @@
     <script src="js/receiver-signature.js?v=9"></script>
     <script src="js/signflow-theme.js"></script>
     <script src="js/envelope-editor.js"></script>
+    <script src="_content/MudBlazor/MudBlazor.min.js"></script>
     <script src="_framework/blazor.web.js"></script>
 </body>
 
diff --git a/EnvelopeGenerator.Server/EnvelopeGenerator.Server/EnvelopeGenerator.Server.csproj b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/EnvelopeGenerator.Server.csproj
index 5fd58752..7147d447 100644
--- a/EnvelopeGenerator.Server/EnvelopeGenerator.Server/EnvelopeGenerator.Server.csproj
+++ b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/EnvelopeGenerator.Server.csproj
@@ -30,6 +30,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.Components.WebAssembly.Server" Version="8.0.22" />
+    <PackageReference Include="MudBlazor" Version="8.0.0" />
     <PackageReference Include="DevExpress.Blazor" Version="25.2.3" />
     <PackageReference Include="DevExpress.Blazor.PdfViewer" Version="25.2.3" />
     <PackageReference Include="DevExpress.Blazor.Reporting.Viewer" Version="25.2.3" />
diff --git a/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Program.cs b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Program.cs
index 3698a76b..ac7991db 100644
--- a/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Program.cs
+++ b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/Program.cs
@@ -32,6 +32,7 @@ using NLog;
 using NLog.Web;
 using Scalar.AspNetCore;
 using System.Globalization;
+using MudBlazor.Services;
 
 var logger = LogManager.Setup().LoadConfigurationFromAppSettings().GetCurrentClassLogger();
 logger.Info("EnvelopeGenerator.Server logging initialized!");
@@ -60,6 +61,7 @@ try
     builder.Services.AddRazorComponents()
         .AddInteractiveServerComponents()
         .AddInteractiveWebAssemblyComponents();
+    builder.Services.AddMudServices();
 
     // Add API Controllers
     builder.Services.AddControllers()
diff --git a/EnvelopeGenerator.Server/EnvelopeGenerator.Server/wwwroot/css/sender-page.css b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/wwwroot/css/sender-page.css
index 02573630..41f3dfc8 100644
--- a/EnvelopeGenerator.Server/EnvelopeGenerator.Server/wwwroot/css/sender-page.css
+++ b/EnvelopeGenerator.Server/EnvelopeGenerator.Server/wwwroot/css/sender-page.css
@@ -1116,57 +1116,71 @@
     z-index: 2;
 }
 
-.sender-create-wizard__progress {
-    position: relative;
-    display: grid;
-    grid-template-columns: repeat(5, minmax(0, 1fr));
-    align-items: center;
-    gap: 0.5rem;
+.sender-create-wizard__stepper-shell {
+    border: 1px solid rgba(126, 34, 206, 0.12);
+    border-radius: 10px;
+    background: rgba(126, 34, 206, 0.04);
+    padding: 0.75rem;
 }
 
-.sender-create-wizard__progress-track {
-    position: absolute;
-    left: 12px;
-    right: 12px;
-    top: 50%;
-    height: 2px;
-    transform: translateY(-50%);
-    background: rgba(126, 34, 206, 0.18);
-    z-index: 0;
+.sender-create-wizard__stepper {
+    margin: 0;
 }
 
-.sender-create-wizard__step {
-    position: relative;
-    z-index: 1;
-    display: flex;
-    justify-content: center;
+.sender-create-wizard__stepper .mud-step {
+    pointer-events: none;
 }
 
-.sender-create-wizard__step-index {
-    width: 24px;
-    height: 24px;
-    border-radius: 999px;
-    display: inline-flex;
-    align-items: center;
-    justify-content: center;
-    font-size: 0.78rem;
+.sender-create-wizard__stepper .mud-stepper-actions,
+.sender-create-wizard__stepper .mud-stepper-action {
+    display: none !important;
+}
+
+.sender-create-wizard__stepper .mud-step-label {
+    color: #1f2937;
+    font-size: 0.86rem;
     font-weight: 700;
+}
+
+.sender-create-wizard__stepper .mud-step-content {
+    color: #64748b;
+}
+
+.sender-create-wizard__stepper .mud-stepper-vertical .mud-stepper-step {
+    margin-bottom: 0.25rem;
+}
+
+.sender-create-wizard__stepper .mud-step-icon {
     color: #64748b;
     background: #f8fafc;
     border: 1px solid rgba(126, 34, 206, 0.25);
 }
 
-.sender-create-wizard__step--active .sender-create-wizard__step-index {
+.sender-create-wizard__stepper .mud-step-completed .mud-step-icon,
+.sender-create-wizard__stepper .mud-step-current .mud-step-icon {
     color: #ffffff;
-    background: linear-gradient(135deg, #7e22ce 0%, #2a5298 100%);
     border-color: transparent;
+}
+
+.sender-create-wizard__stepper .mud-step-current .mud-step-icon {
+    background: linear-gradient(135deg, #7e22ce 0%, #2a5298 100%);
     box-shadow: 0 0 0 3px rgba(126, 34, 206, 0.15);
 }
 
-.sender-create-wizard__step--done .sender-create-wizard__step-index {
-    color: #ffffff;
+.sender-create-wizard__stepper .mud-step-completed .mud-step-icon {
     background: #2a5298;
-    border-color: transparent;
+}
+
+.sender-create-wizard__stepper-description {
+    font-size: 0.8rem;
+    line-height: 1.35;
+    color: #64748b;
+    margin-top: 0.2rem;
+    padding-right: 0.35rem;
+}
+
+.sender-create-wizard__step-content {
+    margin-top: 0.7rem;
 }
 
 .sender-create-wizard__meta {