diff --git a/src/core/DigitalData.MessagingService.Application/EmailReceiving/Queries/ReadEmailViaOAuth2Query.cs b/src/core/DigitalData.MessagingService.Application/EmailReceiving/Queries/ReadEmailViaOAuth2Query.cs
new file mode 100644
index 0000000..51bf42c
--- /dev/null
+++ b/src/core/DigitalData.MessagingService.Application/EmailReceiving/Queries/ReadEmailViaOAuth2Query.cs
@@ -0,0 +1,77 @@
+#if NET
+using AutoMapper;
+using DigitalData.MessagingService.Application.Common.Dto;
+using DigitalData.MessagingService.Application.Common.Dto.MailSearch;
+using DigitalData.MessagingService.Application.Common.Interfaces;
+using DigitalData.MessagingService.Application.Common.Interfaces.Repositories;
+using DigitalData.MessagingService.Application.EmailAccounts.Queries;
+using DigitalData.MessagingService.Application.EmailReceiving.Queries;
+using DigitalData.MessagingService.Domain.Entities;
+using DigitalData.MessagingService.Domain.Exceptions;
+using MediatR;
+using Microsoft.Extensions.Logging;
+
+namespace DigitalData.MessagingService.Application.EmailReceiving.Queries;
+
+/// <summary>
+/// Query to fetch emails from an IMAP mailbox using OAuth2 authentication.
+/// The account must have <c>UseOAuth2 = true</c> and valid OAuth2 credentials configured.
+/// </summary>
+public record ReadEmailViaOAuth2Query : IRequest<ReadEmailQueryResponse>
+{
+    /// <summary>
+    /// Identifies the email account to use.
+    /// </summary>
+    public required GetEmailAccountQuery Account { get; init; }
+
+    /// <summary>
+    /// Mail query used to filter and limit the emails retrieved.
+    /// </summary>
+    public MailSearchFilter Mail { get; init; } = new();
+}
+
+public class ReadEmailViaOAuth2QueryHandler(
+    IMapper Mapper,
+    ILogger<ReadEmailViaOAuth2QueryHandler> Logger,
+    IRepository<EmailAccount> EmailAccountRepo,
+    IReceivedEmailRepository MailRepo,
+    IImapEmailService imapEmailService) : IRequestHandler<ReadEmailViaOAuth2Query, ReadEmailQueryResponse>
+{
+    public async Task<ReadEmailQueryResponse> Handle(ReadEmailViaOAuth2Query request, CancellationToken cancellationToken)
+    {
+        var accounts = await EmailAccountRepo.FindAsync(
+            request.Account.Id is int id ? x => x.Id == id : x => x.Username == request.Account.Username,
+            cancellationToken: cancellationToken);
+
+        if (accounts.Count() > 1)
+            Logger.LogWarning("Multiple email accounts found ({Criteria}). Using first.",
+                request.Account.Id is not null ? $"Id: {request.Account.Id}" : $"Username: {request.Account.Username}");
+
+        var account = accounts.FirstOrDefault()
+            ?? throw new NotFoundException($"No email account found (Id: {request.Account.Id}, Username: {request.Account.Username}).");
+
+        if (!account.UseOAuth2)
+            throw new BadRequestException(
+                $"Account '{account.Username}' (Id: {account.Id}) is not configured for OAuth2. Set UseOAuth2 = true.");
+
+        if (string.IsNullOrWhiteSpace(account.OAuth2ClientId) ||
+            string.IsNullOrWhiteSpace(account.OAuth2ClientSecret))
+            throw new BadRequestException(
+                $"OAuth2 credentials (ClientId, ClientSecret) are not configured for account '{account.Username}'.");
+
+        if (string.IsNullOrWhiteSpace(account.ImapServer))
+            throw new BadRequestException(
+                $"IMAP is not configured for account '{account.Username}' (Id: {account.Id}). Set ImapServer in EmailAccounts configuration.");
+
+        var mails = await MailRepo.FindAsync(request.Mail, account, cancellationToken);
+
+        var lastSync = imapEmailService.GetLastImapSyncDate(account.Id, request.Mail.Folder);
+
+        return new ReadEmailQueryResponse
+        {
+            LastSync = lastSync,
+            Emails = Mapper.Map<IEnumerable<ReceivedEmailDto>>(mails)
+        };
+    }
+}
+#endif
diff --git a/src/core/DigitalData.MessagingService.Application/EmailReceiving/Queries/ReadEmailViaPop3Query.cs b/src/core/DigitalData.MessagingService.Application/EmailReceiving/Queries/ReadEmailViaPop3Query.cs
new file mode 100644
index 0000000..0f3bee0
--- /dev/null
+++ b/src/core/DigitalData.MessagingService.Application/EmailReceiving/Queries/ReadEmailViaPop3Query.cs
@@ -0,0 +1,74 @@
+#if NET
+using AutoMapper;
+using DigitalData.MessagingService.Application.Common.Dto;
+using DigitalData.MessagingService.Application.Common.Dto.MailSearch;
+using DigitalData.MessagingService.Application.Common.Interfaces;
+using DigitalData.MessagingService.Application.Common.Interfaces.Repositories;
+using DigitalData.MessagingService.Application.EmailAccounts.Queries;
+using DigitalData.MessagingService.Application.EmailReceiving.Queries;
+using DigitalData.MessagingService.Domain.Entities;
+using DigitalData.MessagingService.Domain.Exceptions;
+using MediatR;
+using Microsoft.Extensions.Logging;
+
+namespace DigitalData.MessagingService.Application.EmailReceiving.Queries;
+
+/// <summary>
+/// Query to fetch emails from a POP3 mailbox.
+/// Triggers an on-demand sync and returns stored results filtered by <see cref="Mail"/>.
+/// </summary>
+public record ReadEmailViaPop3Query : IRequest<ReadEmailQueryResponse>
+{
+    /// <summary>
+    /// Identifies the email account to use.
+    /// </summary>
+    public required GetEmailAccountQuery Account { get; init; }
+
+    /// <summary>
+    /// Mail query used to filter and limit the emails retrieved from local storage.
+    /// Note: POP3 has no folder concept — all messages are stored under "INBOX".
+    /// </summary>
+    public MailSearchFilter Mail { get; init; } = new();
+}
+
+public class ReadEmailViaPop3QueryHandler(
+    IMapper Mapper,
+    ILogger<ReadEmailViaPop3QueryHandler> Logger,
+    IRepository<EmailAccount> EmailAccountRepo,
+    IReceivedEmailRepository MailRepo,
+    IPop3EmailService pop3EmailService) : IRequestHandler<ReadEmailViaPop3Query, ReadEmailQueryResponse>
+{
+    public async Task<ReadEmailQueryResponse> Handle(ReadEmailViaPop3Query request, CancellationToken cancellationToken)
+    {
+        var accounts = await EmailAccountRepo.FindAsync(
+            request.Account.Id is int id ? x => x.Id == id : x => x.Username == request.Account.Username,
+            cancellationToken: cancellationToken);
+
+        if (accounts.Count() > 1)
+            Logger.LogWarning("Multiple email accounts found ({Criteria}). Using first.",
+                request.Account.Id is not null ? $"Id: {request.Account.Id}" : $"Username: {request.Account.Username}");
+
+        var account = accounts.FirstOrDefault()
+            ?? throw new NotFoundException($"No email account found (Id: {request.Account.Id}, Username: {request.Account.Username}).");
+
+        if (string.IsNullOrWhiteSpace(account.Pop3Server))
+            throw new BadRequestException(
+                $"POP3 is not configured for account '{account.Username}' (Id: {account.Id}). Set Pop3Server in EmailAccounts configuration.");
+
+        // Trigger on-demand POP3 sync before querying local storage
+        await pop3EmailService.SyncEmailsAsync(account, cancellationToken);
+
+        // POP3 has no folder concept — always query INBOX
+        var filter = request.Mail with { Folder = "INBOX" };
+        var mails = await MailRepo.FindAsync(filter, account, cancellationToken);
+
+        var lastSync = pop3EmailService.GetLastPop3SyncDate(account.Id);
+
+        return new ReadEmailQueryResponse
+        {
+            LastSync = lastSync,
+            Emails = Mapper.Map<IEnumerable<ReceivedEmailDto>>(mails)
+        };
+    }
+}
+#endif
diff --git a/src/core/DigitalData.MessagingService.Application/EmailSending/Commands/PublishEmailViaImapCommand.cs b/src/core/DigitalData.MessagingService.Application/EmailSending/Commands/PublishEmailViaImapCommand.cs
new file mode 100644
index 0000000..8d5e391
--- /dev/null
+++ b/src/core/DigitalData.MessagingService.Application/EmailSending/Commands/PublishEmailViaImapCommand.cs
@@ -0,0 +1,81 @@
+#if NET
+using AutoMapper;
+using DigitalData.MessagingService.Application.Common.Dto;
+using DigitalData.MessagingService.Application.Common.Interfaces;
+using DigitalData.MessagingService.Application.Common.Interfaces.Repositories;
+using DigitalData.MessagingService.Application.EmailAccounts.Queries;
+using DigitalData.MessagingService.Domain.Entities;
+using DigitalData.MessagingService.Domain.Exceptions;
+using MediatR;
+using Microsoft.Extensions.Logging;
+using System.Text.Json.Serialization;
+
+namespace DigitalData.MessagingService.Application.EmailSending.Commands;
+
+/// <summary>
+/// Command to send an email using IMAP account credentials (queued via RabbitMQ).
+/// After processing, the sent message is appended to the IMAP Sent Items folder.
+/// </summary>
+public record PublishEmailViaImapCommand : IRequest<Guid>
+{
+    public required GetEmailAccountQuery Sender { get; init; }
+
+    public required IEnumerable<string> Recipients { get; init; }
+
+    public required string Subject { get; init; }
+
+    public required string Body { get; init; }
+
+    public bool IsHtml { get; init; } = true;
+
+    /// <summary>
+    /// IMAP folder to which the sent message will be appended (default: "Sent").
+    /// </summary>
+    public string SentFolder { get; init; } = "Sent";
+
+    [JsonIgnore]
+    internal IEnumerable<EmailAttachmentDto> Attachments { get; private init; } = [];
+
+    public PublishEmailViaImapCommand WithAttachments(IEnumerable<EmailAttachmentDto> attachments)
+        => this with { Attachments = attachments };
+}
+
+public class PublishEmailViaImapCommandHandler(
+    IRepository<EmailAccount> Repo,
+    ISendingEmailPublisher Publisher,
+    IMapper Mapper,
+    ILogger<PublishEmailViaImapCommandHandler> Logger) : IRequestHandler<PublishEmailViaImapCommand, Guid>
+{
+    public async Task<Guid> Handle(PublishEmailViaImapCommand request, CancellationToken cancellationToken)
+    {
+        var senderAccounts = await Repo.FindAsync(
+            request.Sender.Id is int id ? x => x.Id == id : x => x.Username == request.Sender.Username,
+            cancellationToken: cancellationToken);
+
+        if (senderAccounts.Count() > 1)
+            Logger.LogWarning("Multiple email accounts found ({Criteria}). Using first.",
+                request.Sender.Id is not null ? $"Id: {request.Sender.Id}" : $"Username: {request.Sender.Username}");
+
+        var senderAccount = senderAccounts.FirstOrDefault()
+            ?? throw new NotFoundException($"No email account found (Id: {request.Sender.Id}, Username: {request.Sender.Username}).");
+
+        if (string.IsNullOrWhiteSpace(senderAccount.ImapServer))
+            throw new BadRequestException(
+                $"IMAP is not configured for account '{senderAccount.Username}' (Id: {senderAccount.Id}). Set ImapServer in EmailAccounts configuration.");
+
+        var emailContext = Mapper.Map<EmailContext>(request) with { Sender = senderAccount };
+
+        var sendingEmailEvent = new SendingEmailEvent
+        {
+            Id = Guid.NewGuid(),
+            Mail = emailContext,
+            QueuedAt = DateTime.Now,
+            SentFolder = request.SentFolder,
+            UseImapAppend = true
+        };
+
+        await Publisher.EnqueueAsync(sendingEmailEvent, cancellationToken);
+        return sendingEmailEvent.Id;
+    }
+}
+#endif
diff --git a/src/core/DigitalData.MessagingService.Application/EmailSending/Commands/PublishEmailViaOAuth2Command.cs b/src/core/DigitalData.MessagingService.Application/EmailSending/Commands/PublishEmailViaOAuth2Command.cs
new file mode 100644
index 0000000..4804dcd
--- /dev/null
+++ b/src/core/DigitalData.MessagingService.Application/EmailSending/Commands/PublishEmailViaOAuth2Command.cs
@@ -0,0 +1,79 @@
+#if NET
+using AutoMapper;
+using DigitalData.MessagingService.Application.Common.Dto;
+using DigitalData.MessagingService.Application.Common.Interfaces;
+using DigitalData.MessagingService.Application.Common.Interfaces.Repositories;
+using DigitalData.MessagingService.Application.EmailAccounts.Queries;
+using DigitalData.MessagingService.Domain.Entities;
+using DigitalData.MessagingService.Domain.Exceptions;
+using MediatR;
+using Microsoft.Extensions.Logging;
+using System.Text.Json.Serialization;
+
+namespace DigitalData.MessagingService.Application.EmailSending.Commands;
+
+/// <summary>
+/// Command to send an email via SMTP using OAuth2 authentication (queued via RabbitMQ).
+/// The account must have <c>UseOAuth2 = true</c> and valid OAuth2 credentials configured.
+/// </summary>
+public record PublishEmailViaOAuth2Command : IRequest<Guid>
+{
+    public required GetEmailAccountQuery Sender { get; init; }
+
+    public required IEnumerable<string> Recipients { get; init; }
+
+    public required string Subject { get; init; }
+
+    public required string Body { get; init; }
+
+    public bool IsHtml { get; init; } = true;
+
+    [JsonIgnore]
+    internal IEnumerable<EmailAttachmentDto> Attachments { get; private init; } = [];
+
+    public PublishEmailViaOAuth2Command WithAttachments(IEnumerable<EmailAttachmentDto> attachments)
+        => this with { Attachments = attachments };
+}
+
+public class PublishEmailViaOAuth2CommandHandler(
+    IRepository<EmailAccount> Repo,
+    ISendingEmailPublisher Publisher,
+    IMapper Mapper,
+    ILogger<PublishEmailViaOAuth2CommandHandler> Logger) : IRequestHandler<PublishEmailViaOAuth2Command, Guid>
+{
+    public async Task<Guid> Handle(PublishEmailViaOAuth2Command request, CancellationToken cancellationToken)
+    {
+        var senderAccounts = await Repo.FindAsync(
+            request.Sender.Id is int id ? x => x.Id == id : x => x.Username == request.Sender.Username,
+            cancellationToken: cancellationToken);
+
+        if (senderAccounts.Count() > 1)
+            Logger.LogWarning("Multiple email accounts found ({Criteria}). Using first.",
+                request.Sender.Id is not null ? $"Id: {request.Sender.Id}" : $"Username: {request.Sender.Username}");
+
+        var senderAccount = senderAccounts.FirstOrDefault()
+            ?? throw new NotFoundException($"No email account found (Id: {request.Sender.Id}, Username: {request.Sender.Username}).");
+
+        if (!senderAccount.UseOAuth2)
+            throw new BadRequestException(
+                $"Account '{senderAccount.Username}' (Id: {senderAccount.Id}) is not configured for OAuth2. Set UseOAuth2 = true.");
+
+        if (string.IsNullOrWhiteSpace(senderAccount.OAuth2ClientId) ||
+            string.IsNullOrWhiteSpace(senderAccount.OAuth2ClientSecret))
+            throw new BadRequestException(
+                $"OAuth2 credentials (ClientId, ClientSecret) are not configured for account '{senderAccount.Username}'.");
+
+        var emailContext = Mapper.Map<EmailContext>(request) with { Sender = senderAccount };
+
+        var sendingEmailEvent = new SendingEmailEvent
+        {
+            Id = Guid.NewGuid(),
+            Mail = emailContext,
+            QueuedAt = DateTime.Now
+        };
+
+        await Publisher.EnqueueAsync(sendingEmailEvent, cancellationToken);
+        return sendingEmailEvent.Id;
+    }
+}
+#endif