diff --git a/EnvelopeGenerator.Domain/Entities/Config.cs b/EnvelopeGenerator.Domain/Entities/Config.cs
index 0f5d48e5..6a824a46 100644
--- a/EnvelopeGenerator.Domain/Entities/Config.cs
+++ b/EnvelopeGenerator.Domain/Entities/Config.cs
@@ -6,23 +6,23 @@ using System.Text.Json.Serialization;
 namespace EnvelopeGenerator.Domain.Entities
 {
     [Table("TBSIG_CONFIG", Schema = "dbo")]
-    public class Config : IUnique<int>
+    public class Config
     {
         [Column("DOCUMENT_PATH", TypeName = "nvarchar(256)")]
-        public string? DocumentPath { get; init; }
+        public string DocumentPath { get; set; }
 
         [Column("SENDING_PROFILE", TypeName = "int")]
         [Required]
-        public required int SendingProfile { get; init; }
+        public int SendingProfile { get; set; }
 
         [Column("SIGNATURE_HOST", TypeName = "nvarchar(128)")]
-        public string? SignatureHost { get; init; }
+        public string SignatureHost { get; set; }
 
         [Column("EXTERNAL_PROGRAM_NAME", TypeName = "nvarchar(30)")]
-        public string? ExternalProgramName { get; init; }
+        public string ExternalProgramName { get; set; }
 
         [Column("EXPORT_PATH", TypeName = "nvarchar(256)")]
-        public string? ExportPath { get; init; }
+        public string ExportPath { get; set; }
 
         [Obsolete("Configuration does not have an ID; it represents a single table in the database.")]
         [NotMapped]
diff --git a/EnvelopeGenerator.Domain/Entities/DocumentReceiverElement.cs b/EnvelopeGenerator.Domain/Entities/DocumentReceiverElement.cs
index 6d165028..7c98e900 100644
--- a/EnvelopeGenerator.Domain/Entities/DocumentReceiverElement.cs
+++ b/EnvelopeGenerator.Domain/Entities/DocumentReceiverElement.cs
@@ -1,12 +1,11 @@
-using DigitalData.Core.Abstractions;
-using System.ComponentModel;
+using System.ComponentModel;
 using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
 
 namespace EnvelopeGenerator.Domain.Entities
 {
     [Table("TBSIG_DOCUMENT_RECEIVER_ELEMENT", Schema = "dbo")]
-    public class DocumentReceiverElement : IUnique<int>
+    public class DocumentReceiverElement
     {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
@@ -57,7 +56,7 @@ namespace EnvelopeGenerator.Domain.Entities
         public bool Required { get; set; }
 
         [Column("TOOLTIP")]
-        public string? Tooltip { get; set; }
+        public string Tooltip { get; set; }
 
         [Required]
         [Column("READ_ONLY")]
@@ -75,13 +74,13 @@ namespace EnvelopeGenerator.Domain.Entities
         public DateTime AddedWhen { get; set; }
 
         [Column("CHANGED_WHEN", TypeName = "datetime")]
-        public DateTime? ChangedWhen { get; set; }
+        public DateTime ChangedWhen { get; set; }
 
         [ForeignKey("DocumentId")]
-        public virtual EnvelopeDocument? Document { get; set; }
+        public virtual EnvelopeDocument Document { get; set; }
 
         [ForeignKey("ReceiverId")]
-        public virtual Receiver? Receiver { get; set; }
+        public virtual Receiver Receiver { get; set; }
 
         [NotMapped]
         public double Top => Math.Round(Y, 5);
diff --git a/EnvelopeGenerator.Domain/Entities/DocumentStatus.cs b/EnvelopeGenerator.Domain/Entities/DocumentStatus.cs
index dd243b76..0ec6e777 100644
--- a/EnvelopeGenerator.Domain/Entities/DocumentStatus.cs
+++ b/EnvelopeGenerator.Domain/Entities/DocumentStatus.cs
@@ -1,11 +1,10 @@
-using DigitalData.Core.Abstractions;
-using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
 
 namespace EnvelopeGenerator.Domain.Entities
 {
     [Table("TBSIG_DOCUMENT_STATUS", Schema = "dbo")]
-    public class DocumentStatus : IUnique<int>
+    public class DocumentStatus
     {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
@@ -25,22 +24,22 @@ namespace EnvelopeGenerator.Domain.Entities
         public int Status { get; set; }
 
         [Column("STATUS_CHANGED_WHEN", TypeName = "datetime")]
-        public DateTime? StatusChangedWhen { get; set; }
+        public DateTime StatusChangedWhen { get; set; }
 
         [Column("VALUE", TypeName = "nvarchar(max)")]
-        public string? Value { get; set; }
+        public string Value { get; set; }
 
         [Required]
         [Column("ADDED_WHEN", TypeName = "datetime")]
         public DateTime AddedWhen { get; set; }
 
         [Column("CHANGED_WHEN", TypeName = "datetime")]
-        public DateTime? ChangedWhen { get; set; }
+        public DateTime ChangedWhen { get; set; }
 
         [ForeignKey("EnvelopeId")]
-        public virtual Envelope? Envelope { get; set; }
+        public virtual Envelope Envelope { get; set; }
 
         [ForeignKey("ReceiverId")]
-        public virtual Receiver? Receiver { get; set; }
+        public virtual Receiver Receiver { get; set; }
     }
 }
\ No newline at end of file
diff --git a/EnvelopeGenerator.Domain/Entities/EmailTemplate.cs b/EnvelopeGenerator.Domain/Entities/EmailTemplate.cs
index 689df6b9..d81915b0 100644
--- a/EnvelopeGenerator.Domain/Entities/EmailTemplate.cs
+++ b/EnvelopeGenerator.Domain/Entities/EmailTemplate.cs
@@ -1,12 +1,11 @@
-using DigitalData.Core.Abstractions;
-using System.ComponentModel;
+using System.ComponentModel;
 using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
 
 namespace EnvelopeGenerator.Domain.Entities
 {
     [Table("TBSIG_EMAIL_TEMPLATE", Schema = "dbo")]
-    public class EmailTemplate : IUnique<int>
+    public class EmailTemplate
     {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
@@ -14,13 +13,13 @@ namespace EnvelopeGenerator.Domain.Entities
         public int Id { get; set; }
 
         [Column("NAME", TypeName = "nvarchar(64)")]
-        public string? Name { get; set; }
+        public string Name { get; set; }
 
         [Column("BODY", TypeName = "nvarchar(max)")]
-        public string? Body { get; set; }
+        public string Body { get; set; }
 
         [Column("SUBJECT", TypeName = "nvarchar(512)")]
-        public string? Subject { get; set; }
+        public string Subject { get; set; }
 
         [Required]
         [Column("ADDED_WHEN", TypeName = "datetime")]
@@ -28,6 +27,6 @@ namespace EnvelopeGenerator.Domain.Entities
         public DateTime AddedWhen { get; set; }
 
         [Column("CHANGED_WHEN", TypeName = "datetime")]
-        public DateTime? ChangedWhen { get; set; }
+        public DateTime ChangedWhen { get; set; }
     }
 }
\ No newline at end of file
diff --git a/EnvelopeGenerator.Domain/Entities/Envelope.cs b/EnvelopeGenerator.Domain/Entities/Envelope.cs
index 1711113f..ff24fe35 100644
--- a/EnvelopeGenerator.Domain/Entities/Envelope.cs
+++ b/EnvelopeGenerator.Domain/Entities/Envelope.cs
@@ -1,12 +1,11 @@
-using DigitalData.Core.Abstractions;
-using EnvelopeGenerator.Common;
+using EnvelopeGenerator.Common;
 using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
 
 namespace EnvelopeGenerator.Domain.Entities
 {
     [Table("TBSIG_ENVELOPE", Schema = "dbo")]
-    public class Envelope : IUnique<int>
+    public class Envelope
     {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
@@ -26,86 +25,86 @@ namespace EnvelopeGenerator.Domain.Entities
 
         [Required]
         [Column("ENVELOPE_UUID", TypeName = "nvarchar(36)")]
-        public required string Uuid { get; init; }
+        public string Uuid { get; set; }
 
         [Column("MESSAGE", TypeName = "nvarchar(max)")]
-        public string? Message { get; set; }
+        public string Message { get; set; }
 
         [Column("EXPIRES_WHEN", TypeName = "datetime")]
-        public DateTime? ExpiresWhen { get; set; }
+        public DateTime ExpiresWhen { get; set; }
 
         [Column("EXPIRES_WARNING_WHEN", TypeName = "datetime")]
-        public DateTime? ExpiresWarningWhen { get; set; }
+        public DateTime ExpiresWarningWhen { get; set; }
 
         [Required]
         [Column("ADDED_WHEN", TypeName = "datetime")]
         public DateTime AddedWhen { get; set; }
 
         [Column("CHANGED_WHEN", TypeName = "datetime")]
-        public DateTime? ChangedWhen { get; set; }
+        public DateTime ChangedWhen { get; set; }
 
         [Column("TITLE", TypeName = "nvarchar(128)")]
-        public string? Title { get; set; }
+        public string Title { get; set; }
 
         [Column("CONTRACT_TYPE")]
-        public int? ContractType { get; set; }
+        public int ContractType { get; set; }
 
         [Column("LANGUAGE", TypeName = "nvarchar(5)")]
-        public string? Language { get; set; }
+        public string Language { get; set; }
 
         [Column("SEND_REMINDER_EMAILS")]
-        public bool? SendReminderEmails { get; set; }
+        public bool SendReminderEmails { get; set; }
 
         [Column("FIRST_REMINDER_DAYS")]
-        public int? FirstReminderDays { get; set; }
+        public int FirstReminderDays { get; set; }
 
         [Column("REMINDER_INTERVAL_DAYS")]
-        public int? ReminderIntervalDays { get; set; }
+        public int ReminderIntervalDays { get; set; }
 
         [Column("ENVELOPE_TYPE")]
-        public int? EnvelopeTypeId { get; set; }
+        public int EnvelopeTypeId { get; set; }
 
         [Column("CERTIFICATION_TYPE")]
-        public int? CertificationType { get; set; }
+        public int CertificationType { get; set; }
 
         [Column("USE_ACCESS_CODE")]
-        public bool? UseAccessCode { get; set; }
+        public bool UseAccessCode { get; set; }
 
         [Column("FINAL_EMAIL_TO_CREATOR")]
-        public int? FinalEmailToCreator { get; set; }
+        public int FinalEmailToCreator { get; set; }
 
         [Column("FINAL_EMAIL_TO_RECEIVERS")]
-        public int? FinalEmailToReceivers { get; set; }
+        public int FinalEmailToReceivers { get; set; }
 
         [Column("EXPIRES_WHEN_DAYS")]
-        public int? ExpiresWhenDays { get; set; }
+        public int ExpiresWhenDays { get; set; }
 
         [Column("EXPIRES_WARNING_WHEN_DAYS")]
-        public int? ExpiresWarningWhenDays { get; set; }
+        public int ExpiresWarningWhenDays { get; set; }
 
         [Column("TFA_ENABLED", TypeName = "bit")]
         public bool TFAEnabled { get; set; }
 
         [Column("DOC_RESULT", TypeName = "varbinary(max)")]
-        public byte[]? DocResult { get; init; }
+        public byte[] DocResult { get; set; }
 
         /// <summary>
         /// The sender of envelope
         /// </summary>
         [ForeignKey("UserId")]
-        public DigitalData.UserManager.Domain.Entities.User? User { get; set; }
+        public DigitalData.UserManager.Domain.Entities.User User { get; set; }
 
         [ForeignKey("EnvelopeTypeId")]
-        public EnvelopeType? EnvelopeType { get; set; }
+        public EnvelopeType EnvelopeType { get; set; }
 
         [NotMapped]
-        public string? EnvelopeTypeTitle => EnvelopeType?.Title;
+        public string EnvelopeTypeTitle => EnvelopeType.Title;
 
         [NotMapped]
         public bool IsAlreadySent => Status > (int) Constants.EnvelopeStatus.EnvelopeSaved;
 
-        public IEnumerable<EnvelopeDocument>? Documents { get; set; }
+        public IEnumerable<EnvelopeDocument> Documents { get; set; }
 
-        public IEnumerable<EnvelopeHistory>? History { get; set; }
+        public IEnumerable<EnvelopeHistory> History { get; set; }
     }
 }
\ No newline at end of file
diff --git a/EnvelopeGenerator.Domain/Entities/EnvelopeCertificate.cs b/EnvelopeGenerator.Domain/Entities/EnvelopeCertificate.cs
index f6450954..c8bd8c6e 100644
--- a/EnvelopeGenerator.Domain/Entities/EnvelopeCertificate.cs
+++ b/EnvelopeGenerator.Domain/Entities/EnvelopeCertificate.cs
@@ -1,11 +1,10 @@
-using DigitalData.Core.Abstractions;
-using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
 
 namespace EnvelopeGenerator.Domain.Entities
 {
     [Table("TBSIG_ENVELOPE_CERTIFICATE", Schema = "dbo")]
-    public class EnvelopeCertificate : IUnique<int>
+    public class EnvelopeCertificate
     {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
@@ -18,11 +17,11 @@ namespace EnvelopeGenerator.Domain.Entities
 
         [Required]
         [Column("ENVELOPE_UUID", TypeName = "nvarchar(36)")]
-        public required string EnvelopeUuid { get; set; }
+        public string EnvelopeUuid { get; set; }
 
         [Required]
         [Column("ENVELOPE_SUBJECT", TypeName = "nvarchar(512)")]
-        public required string EnvelopeSubject { get; set; }
+        public string EnvelopeSubject { get; set; }
 
         [Required]
         [Column("CREATOR_ID")]
@@ -30,11 +29,11 @@ namespace EnvelopeGenerator.Domain.Entities
 
         [Required]
         [Column("CREATOR_NAME", TypeName = "nvarchar(128)")]
-        public required string CreatorName { get; set; }
+        public string CreatorName { get; set; }
 
         [Required]
         [Column("CREATOR_EMAIL", TypeName = "nvarchar(128)")]
-        public required string CreatorEmail { get; set; }
+        public string CreatorEmail { get; set; }
 
         [Required]
         [Column("ENVELOPE_STATUS")]
diff --git a/EnvelopeGenerator.Domain/Entities/EnvelopeDocument.cs b/EnvelopeGenerator.Domain/Entities/EnvelopeDocument.cs
index 22aa3b2b..481b7058 100644
--- a/EnvelopeGenerator.Domain/Entities/EnvelopeDocument.cs
+++ b/EnvelopeGenerator.Domain/Entities/EnvelopeDocument.cs
@@ -1,27 +1,27 @@
-using DigitalData.Core.Abstractions;
-using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
 
-namespace EnvelopeGenerator.Domain.Entities;
-
-[Table("TBSIG_ENVELOPE_DOCUMENT", Schema = "dbo")]
-public class EnvelopeDocument : IUnique<int>
+namespace EnvelopeGenerator.Domain.Entities
 {
-    [Key]
-    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
-    [Column("GUID")]
-    public int Id { get; set; }
+    [Table("TBSIG_ENVELOPE_DOCUMENT", Schema = "dbo")]
+    public class EnvelopeDocument
+    {
+        [Key]
+        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
+        [Column("GUID")]
+        public int Id { get; set; }
 
-    [Required]
-    [Column("ENVELOPE_ID")]
-    public int EnvelopeId { get; set; }
+        [Required]
+        [Column("ENVELOPE_ID")]
+        public int EnvelopeId { get; set; }
 
-    [Required]
-    [Column("ADDED_WHEN", TypeName = "datetime")]
-    public required DateTime AddedWhen { get; set; }
+        [Required]
+        [Column("ADDED_WHEN", TypeName = "datetime")]
+        public DateTime AddedWhen { get; set; }
 
-    [Column("BYTE_DATA", TypeName = "varbinary(max)")]
-    public byte[]? ByteData { get; init; }
+        [Column("BYTE_DATA", TypeName = "varbinary(max)")]
+        public byte[] ByteData { get; set; }
 
-    public IEnumerable<DocumentReceiverElement>? Elements { get; set; }
+        public IEnumerable<DocumentReceiverElement> Elements { get; set; }
+    }
 }
\ No newline at end of file
diff --git a/EnvelopeGenerator.Domain/Entities/EnvelopeHistory.cs b/EnvelopeGenerator.Domain/Entities/EnvelopeHistory.cs
index c14e8903..7135ea89 100644
--- a/EnvelopeGenerator.Domain/Entities/EnvelopeHistory.cs
+++ b/EnvelopeGenerator.Domain/Entities/EnvelopeHistory.cs
@@ -1,12 +1,10 @@
-using DigitalData.Core.Abstractions;
-using DigitalData.UserManager.Domain.Entities;
-using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
 
 namespace EnvelopeGenerator.Domain.Entities
 {
     [Table("TBSIG_ENVELOPE_HISTORY", Schema = "dbo")]
-    public class EnvelopeHistory : IUnique<long>
+    public class EnvelopeHistory
     {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
@@ -19,7 +17,7 @@ namespace EnvelopeGenerator.Domain.Entities
 
         [Required]
         [Column("USER_REFERENCE", TypeName = "nvarchar(128)")]
-        public required string UserReference { get; init; }
+        public string UserReference { get; set; }
 
         [Required]
         [Column("STATUS")]
@@ -31,15 +29,15 @@ namespace EnvelopeGenerator.Domain.Entities
         public DateTime AddedWhen { get; set; }
 
         [Column("ACTION_DATE", TypeName = "datetime")]
-        public DateTime? ActionDate { get; set; }
+        public DateTime ActionDate { get; set; }
 
         [Column("COMMENT", TypeName = "nvarchar(max)")]
-        public string? Comment { get; set; }
+        public string Comment { get; set; }
 
         [ForeignKey("UserReference")]
-        public virtual User? Sender { get; set; }
+        public virtual User Sender { get; set; }
 
         [ForeignKey("UserReference")]
-        public virtual Receiver? Receiver { get; set; }
+        public virtual Receiver Receiver { get; set; }
     }
 }
\ No newline at end of file
diff --git a/EnvelopeGenerator.Domain/Entities/EnvelopeReceiver.cs b/EnvelopeGenerator.Domain/Entities/EnvelopeReceiver.cs
index e1374b3e..248f98d7 100644
--- a/EnvelopeGenerator.Domain/Entities/EnvelopeReceiver.cs
+++ b/EnvelopeGenerator.Domain/Entities/EnvelopeReceiver.cs
@@ -6,9 +6,9 @@ namespace EnvelopeGenerator.Domain.Entities
     public class EnvelopeReceiver : EnvelopeReceiverBase
     {
         [ForeignKey("EnvelopeId")]
-        public Envelope? Envelope { get; set; }
+        public Envelope Envelope { get; set; }
 
         [ForeignKey("ReceiverId")]
-        public Receiver? Receiver { get; set; }
+        public Receiver Receiver { get; set; }
     }
 }
\ No newline at end of file
diff --git a/EnvelopeGenerator.Domain/Entities/EnvelopeReceiverBase.cs b/EnvelopeGenerator.Domain/Entities/EnvelopeReceiverBase.cs
index 283d11f0..8e2312c3 100644
--- a/EnvelopeGenerator.Domain/Entities/EnvelopeReceiverBase.cs
+++ b/EnvelopeGenerator.Domain/Entities/EnvelopeReceiverBase.cs
@@ -1,11 +1,10 @@
-using DigitalData.Core.Abstractions;
-using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
 
 namespace EnvelopeGenerator.Domain.Entities
 {
     [Table("TBSIG_ENVELOPE_RECEIVER", Schema = "dbo")]
-    public class EnvelopeReceiverBase : IUnique<(int Envelope, int Receiver)>
+    public class EnvelopeReceiverBase
     {
         [Key]
         [Column("ENVELOPE_ID")]
@@ -20,31 +19,31 @@ namespace EnvelopeGenerator.Domain.Entities
         public int Sequence { get; set; }
 
         [Column("NAME", TypeName = "nvarchar(128)")]
-        public string? Name { get; set; }
+        public string Name { get; set; }
 
         [Column("JOB_TITLE", TypeName = "nvarchar(128)")]
-        public string? JobTitle { get; set; }
+        public string JobTitle { get; set; }
 
         [Column("COMPANY_NAME", TypeName = "nvarchar(128)")]
-        public string? CompanyName { get; set; }
+        public string CompanyName { get; set; }
 
         [Column("PRIVATE_MESSAGE", TypeName = "nvarchar(max)")]
-        public string? PrivateMessage { get; set; }
+        public string PrivateMessage { get; set; }
 
         [Column("ACCESS_CODE", TypeName = "nvarchar(64)")]
-        public string? AccessCode { get; set; }
+        public string AccessCode { get; set; }
 
         [Required]
         [Column("ADDED_WHEN", TypeName = "datetime")]
         public DateTime AddedWhen { get; set; }
 
         [Column("CHANGED_WHEN", TypeName = "datetime")]
-        public DateTime? ChangedWhen { get; set; }
+        public DateTime ChangedWhen { get; set; }
 
         [Column("PHONE_NUMBER")]
         [StringLength(20)]
         [RegularExpression(@"^\+[0-9]+$", ErrorMessage = "Phone number must start with '+' followed by digits.")]
-        public string? PhoneNumber { get; set; }
+        public string PhoneNumber { get; set; }
         
         [NotMapped]
         public (int Envelope, int Receiver) Id => (Envelope: EnvelopeId, Receiver: ReceiverId);
diff --git a/EnvelopeGenerator.Domain/Entities/EnvelopeReceiverReadOnly.cs b/EnvelopeGenerator.Domain/Entities/EnvelopeReceiverReadOnly.cs
index c7e9fc5b..fafda5d2 100644
--- a/EnvelopeGenerator.Domain/Entities/EnvelopeReceiverReadOnly.cs
+++ b/EnvelopeGenerator.Domain/Entities/EnvelopeReceiverReadOnly.cs
@@ -1,52 +1,50 @@
 using System.ComponentModel.DataAnnotations.Schema;
 using System.ComponentModel.DataAnnotations;
-using DigitalData.Core.Abstractions;
-using DigitalData.EmailProfilerDispatcher.Abstraction.Attributes;
 
 namespace EnvelopeGenerator.Domain.Entities
 {
     [Table("TBSIG_ENVELOPE_RECEIVER_READ_ONLY")]
-    public class EnvelopeReceiverReadOnly : IUnique<long>
+    public class EnvelopeReceiverReadOnly
     {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
         [Column("GUID")]
-        public long Id { get; init; }
+        public long Id { get; set; }
 
         [Column("ENVELOPE_ID")]
         [Required]
-        public long EnvelopeId { get; init; }
+        public long EnvelopeId { get; set; }
 
         //TODO: remove NotMapped attribute when EnvelopeId data type is standardized
         [NotMapped]
-        public Envelope? Envelope { get; set; }
+        public Envelope Envelope { get; set; }
 
         [Column("RECEIVER_MAIL")]
         [Required]
         [StringLength(250)]
         [TemplatePlaceholder("NAME_RECEIVER")]
-        public required string ReceiverMail { get; init; }
+        public string ReceiverMail { get; set; }
 
         [Column("DATE_VALID")]
         [Required]
-        public DateTime DateValid { get; init; }
+        public DateTime DateValid { get; set; }
 
         [Column("ADDED_WHO")]
         [Required]
         [StringLength(100)]
-        public required string AddedWho { get; init; }
+        public string AddedWho { get; set; }
 
-        public Receiver? Receiver { get; init; }
+        public Receiver Receiver { get; set; }
 
         [Column("ADDED_WHEN")]
         [Required]
-        public DateTime AddedWhen { get; init; }
+        public DateTime AddedWhen { get; set; }
 
         [Column("CHANGED_WHO")]
         [StringLength(100)]
-        public string? ChangedWho { get; init; }
+        public string ChangedWho { get; set; }
 
         [Column("CHANGED_WHEN")]
-        public DateTime? ChangedWhen { get; init; }
+        public DateTime ChangedWhen { get; set; }
     }
 }
\ No newline at end of file
diff --git a/EnvelopeGenerator.Domain/Entities/EnvelopeType.cs b/EnvelopeGenerator.Domain/Entities/EnvelopeType.cs
index bd837e81..740ce22f 100644
--- a/EnvelopeGenerator.Domain/Entities/EnvelopeType.cs
+++ b/EnvelopeGenerator.Domain/Entities/EnvelopeType.cs
@@ -5,7 +5,7 @@ using System.ComponentModel.DataAnnotations.Schema;
 namespace EnvelopeGenerator.Domain.Entities
 {
     [Table("TBSIG_ENVELOPE_TYPE", Schema = "dbo")]
-    public class EnvelopeType : IUnique<int>
+    public class EnvelopeType
     {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
@@ -14,46 +14,46 @@ namespace EnvelopeGenerator.Domain.Entities
 
         [Required]
         [Column("TITLE", TypeName = "nvarchar(128)")]
-        public required string Title { get; set; }
+        public string Title { get; set; }
 
         [Column("LANGUAGE", TypeName = "nvarchar(5)")]
-        public string? Language { get; set; }
+        public string Language { get; set; }
 
         [Column("EXPIRES_DAYS")]
-        public int? ExpiresDays { get; set; }
+        public int ExpiresDays { get; set; }
 
         [Column("CERTIFICATION_TYPE")]
-        public int? CertificationType { get; set; }
+        public int CertificationType { get; set; }
 
         [Column("USE_ACCESS_CODE")]
-        public bool? UseAccessCode { get; set; }
+        public bool UseAccessCode { get; set; }
 
         [Column("FINAL_EMAIL_TO_CREATOR")]
-        public int? FinalEmailToCreator { get; set; }
+        public int FinalEmailToCreator { get; set; }
 
         [Column("FINAL_EMAIL_TO_RECEIVERS")]
-        public int? FinalEmailToReceivers { get; set; }
+        public int FinalEmailToReceivers { get; set; }
 
         [Required]
         [Column("ADDED_WHEN", TypeName = "datetime")]
         public DateTime AddedWhen { get; set; }
 
         [Column("CHANGED_WHEN", TypeName = "datetime")]
-        public DateTime? ChangedWhen { get; set; }
+        public DateTime ChangedWhen { get; set; }
 
         [Column("EXPIRES_WARNING_DAYS")]
-        public int? ExpiresWarningDays { get; set; }
+        public int ExpiresWarningDays { get; set; }
 
         [Column("SEND_REMINDER_EMAILS")]
-        public bool? SendReminderEmails { get; set; }
+        public bool SendReminderEmails { get; set; }
 
         [Column("FIRST_REMINDER_DAYS")]
-        public int? FirstReminderDays { get; set; }
+        public int FirstReminderDays { get; set; }
 
         [Column("REMINDER_INTERVAL_DAYS")]
-        public int? ReminderIntervalDays { get; set; }
+        public int ReminderIntervalDays { get; set; }
 
         [Column("CONTRACT_TYPE")]
-        public int? ContractType { get; set; }
+        public int ContractType { get; set; }
     }
 }
\ No newline at end of file
diff --git a/EnvelopeGenerator.Domain/Entities/Receiver.cs b/EnvelopeGenerator.Domain/Entities/Receiver.cs
index 0e757cf9..094fe435 100644
--- a/EnvelopeGenerator.Domain/Entities/Receiver.cs
+++ b/EnvelopeGenerator.Domain/Entities/Receiver.cs
@@ -1,34 +1,34 @@
-using DigitalData.Core.Abstractions;
-using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
 
-namespace EnvelopeGenerator.Domain.Entities;
-
-[Table("TBSIG_RECEIVER", Schema = "dbo")]
-public class Receiver : IUnique<int>
+namespace EnvelopeGenerator.Domain.Entities
 {
-    [Key]
-    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
-    [Column("GUID")]
-    public int Id { get; set; }
-    
-    [Required, EmailAddress]
-    [Column("EMAIL_ADDRESS", TypeName = "nvarchar(128)")]
-    public required string EmailAddress { get; set; }
+    [Table("TBSIG_RECEIVER", Schema = "dbo")]
+    public class Receiver
+    {
+        [Key]
+        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
+        [Column("GUID")]
+        public int Id { get; set; }
 
-    [Required]
-    [Column("SIGNATURE", TypeName = "nvarchar(64)")]
-    public required string Signature { get; set; }
+        [Required, EmailAddress]
+        [Column("EMAIL_ADDRESS", TypeName = "nvarchar(128)")]
+        public string EmailAddress { get; set; }
 
-    [Required]
-    [Column("ADDED_WHEN", TypeName = "datetime")]
-    public DateTime AddedWhen { get; set; }
+        [Required]
+        [Column("SIGNATURE", TypeName = "nvarchar(64)")]
+        public string Signature { get; set; }
 
-    [Column("TOTP_SECRET_KEY", TypeName = "nvarchar(MAX)")]
-    public string? TotpSecretkey { get; set; }
+        [Required]
+        [Column("ADDED_WHEN", TypeName = "datetime")]
+        public DateTime AddedWhen { get; set; }
 
-    [Column("TFA_REG_DEADLINE", TypeName = "datetime")]
-    public DateTime? TfaRegDeadline { get; set; }
+        [Column("TOTP_SECRET_KEY", TypeName = "nvarchar(MAX)")]
+        public string TotpSecretkey { get; set; }
 
-    public IEnumerable<EnvelopeReceiver>? EnvelopeReceivers { get; init; }
+        [Column("TFA_REG_DEADLINE", TypeName = "datetime")]
+        public DateTime TfaRegDeadline { get; set; }
+
+        public IEnumerable<EnvelopeReceiver> EnvelopeReceivers { get; set; }
+    }
 }
\ No newline at end of file
diff --git a/EnvelopeGenerator.Domain/Entities/UserReceiver.cs b/EnvelopeGenerator.Domain/Entities/UserReceiver.cs
index c2fc7c0c..9b221297 100644
--- a/EnvelopeGenerator.Domain/Entities/UserReceiver.cs
+++ b/EnvelopeGenerator.Domain/Entities/UserReceiver.cs
@@ -1,11 +1,10 @@
-using DigitalData.Core.Abstractions;
-using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
 
 namespace EnvelopeGenerator.Domain.Entities
 {
     [Table("TBSIG_USER_RECEIVER", Schema = "dbo")]
-    public class UserReceiver : IUnique<int>
+    public class UserReceiver
     {
         [Key]
         [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
@@ -22,16 +21,16 @@ namespace EnvelopeGenerator.Domain.Entities
 
         [Required]
         [Column("NAME", TypeName = "nvarchar(128)")]
-        public required string Name { get; set; }
+        public string Name { get; set; }
 
         [Column("COMPANY_NAME", TypeName = "nvarchar(128)")]
-        public string? CompanyName { get; set; }
+        public string CompanyName { get; set; }
 
         [Column("JOB_TITLE", TypeName = "nvarchar(128)")]
-        public string? JobTitle { get; set; }
+        public string JobTitle { get; set; }
 
         [Required]
         [Column("ADDED_WHEN", TypeName = "datetime")]
-        public required DateTime AddedWhen { get; init; }
+        public DateTime AddedWhen { get; set; }
     }
 }
\ No newline at end of file
diff --git a/EnvelopeGenerator.Domain/EnvelopeGenerator.Domain.csproj b/EnvelopeGenerator.Domain/EnvelopeGenerator.Domain.csproj
index 97b0ca90..38cf73d7 100644
--- a/EnvelopeGenerator.Domain/EnvelopeGenerator.Domain.csproj
+++ b/EnvelopeGenerator.Domain/EnvelopeGenerator.Domain.csproj
@@ -1,15 +1,13 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net7.0;net8.0;net9.0</TargetFrameworks>
+    <TargetFrameworks>net462;net7.0;net8.0;net9.0</TargetFrameworks>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
-  <ItemGroup>
-    <PackageReference Include="DigitalData.Core.Abstractions" Version="3.6.0" />
-    <PackageReference Include="DigitalData.EmailProfilerDispatcher.Abstraction" Version="3.0.0" />
-    <PackageReference Include="UserManager.Domain" Version="3.0.2" />
+  <ItemGroup Condition="'$(TargetFramework)' == 'net462'">
+	  <PackageReference Include="System.ComponentModel.Annotations" Version="4.7.0" />
   </ItemGroup>
 
   <ItemGroup>