diff --git a/src/core/DigitalData.MessagingService.Application/Common/Dto/EmailAccounts/EmailAccountDto.cs b/src/core/DigitalData.MessagingService.Application/Common/Dto/EmailAccounts/EmailAccountDto.cs
new file mode 100644
index 0000000..a531a42
--- /dev/null
+++ b/src/core/DigitalData.MessagingService.Application/Common/Dto/EmailAccounts/EmailAccountDto.cs
@@ -0,0 +1,46 @@
+namespace DigitalData.MessagingService.Application.Common.Dto.EmailAccounts;
+
+/// <summary>
+/// DTO for a single email account configuration.
+/// </summary>
+public record EmailAccountDto
+{
+    /// <summary>
+    /// Logical name to identify this account (e.g. "default", "support").
+    /// </summary>
+    public int Id { get; set; }
+
+#if NET
+    public required string Username { get; set; }
+#else
+    public string Username { get; set; } = null!;
+#endif
+
+#if NET
+    public required string SmtpServer { get; set; }
+#else
+    public string SmtpServer { get; set; } = null!;
+#endif
+
+    public int SmtpPort { get; set; }
+
+    public bool SmtpUseSsl { get; set; }
+
+    public bool UseOAuth2 { get; set; }
+
+    /// <summary>
+    /// IMAP server hostname (e.g. "imap.example.com").
+    /// Leave empty when this account is send-only.
+    /// </summary>
+    public string? ImapServer { get; set; }
+
+    /// <summary>
+    /// IMAP server port (993 for SSL, 143 for plain/STARTTLS).
+    /// </summary>
+    public int ImapPort { get; set; } = 993;
+
+    /// <summary>
+    /// Use SSL/TLS when connecting to the IMAP server.
+    /// </summary>
+    public bool ImapUseSsl { get; set; } = true;
+}
\ No newline at end of file
diff --git a/src/core/DigitalData.MessagingService.Application/Common/Dto/EmailAccounts/EmailAccountModificationDto.cs b/src/core/DigitalData.MessagingService.Application/Common/Dto/EmailAccounts/EmailAccountModificationDto.cs
new file mode 100644
index 0000000..6f2baa1
--- /dev/null
+++ b/src/core/DigitalData.MessagingService.Application/Common/Dto/EmailAccounts/EmailAccountModificationDto.cs
@@ -0,0 +1,47 @@
+namespace DigitalData.MessagingService.Application.Common.Dto.EmailAccounts;
+
+/// <summary>
+/// DTO for a single email account configuration.
+/// </summary>
+public record EmailAccountModificationDto
+{
+#if NET
+    public required string Username { get; set; }
+#else
+    public string Username { get; set; } = null!;
+#endif
+
+#if NET
+    public required string Password { get; set; }
+#else
+    public string Password { get; set; } = null!;
+#endif
+
+#if NET
+    public required string SmtpServer { get; set; }
+#else
+    public string SmtpServer { get; set; } = null!;
+#endif
+
+    public int SmtpPort { get; set; }
+
+    public bool SmtpUseSsl { get; set; }
+
+    public bool UseOAuth2 { get; set; }
+
+    /// <summary>
+    /// IMAP server hostname (e.g. "imap.example.com").
+    /// Leave empty when this account is send-only.
+    /// </summary>
+    public string? ImapServer { get; set; }
+
+    /// <summary>
+    /// IMAP server port (993 for SSL, 143 for plain/STARTTLS).
+    /// </summary>
+    public int ImapPort { get; set; } = 993;
+
+    /// <summary>
+    /// Use SSL/TLS when connecting to the IMAP server.
+    /// </summary>
+    public bool ImapUseSsl { get; set; } = true;
+}
\ No newline at end of file
diff --git a/src/core/DigitalData.MessagingService.Application/Common/ValueObjects/Modification.cs b/src/core/DigitalData.MessagingService.Application/Common/ValueObjects/Modification.cs
new file mode 100644
index 0000000..df815f6
--- /dev/null
+++ b/src/core/DigitalData.MessagingService.Application/Common/ValueObjects/Modification.cs
@@ -0,0 +1,6 @@
+namespace DigitalData.MessagingService.Application.Common.ValueObjects;
+
+public enum Modification
+{
+    Upsert
+}