初步完成邮件功能

DMS.Application/DTOs/SendEmailRequest.cs

@@ -0,0 +1,43 @@
+namespace DMS.Application.DTOs
+{
+    /// <summary>
+    /// 发送邮件请求DTO
+    /// </summary>
+    public class SendEmailRequest
+    {
+        /// <summary>
+        /// 关联的邮件账户ID
+        /// </summary>
+        public int EmailAccountId { get; set; }
+
+        /// <summary>
+        /// 收件人邮箱地址（多个用分号分隔）
+        /// </summary>
+        public string To { get; set; }
+
+        /// <summary>
+        /// 抄送邮箱地址（多个用分号分隔）
+        /// </summary>
+        public string? Cc { get; set; }
+
+        /// <summary>
+        /// 密送邮箱地址（多个用分号分隔）
+        /// </summary>
+        public string? Bcc { get; set; }
+
+        /// <summary>
+        /// 邮件主题
+        /// </summary>
+        public string Subject { get; set; }
+
+        /// <summary>
+        /// 邮件正文
+        /// </summary>
+        public string Body { get; set; }
+
+        /// <summary>
+        /// 是否为HTML格式
+        /// </summary>
+        public bool IsHtml { get; set; } = true;
+    }
+}