public void SendAttachmentTest() { GlobalMailOptions.SmtpServerInfo = new SmtpServerInfo("smtp.189.cn", "*****@*****.**", ""); GlobalMailOptions.DefaultTimeOut = 1500; var mailMessage = new MailMessage { To = { new MailAddress("") }, CC = { new MailAddress("") }, Subject = "测试主题", Body = "测试内容" }; var filePath1 = System.IO.Path.Combine(AppDomain.CurrentDomain.SetupInformation.ApplicationBase, $"{Guid.NewGuid():N}.txt"); File.WriteAllText(filePath1, "test attachment 1", Encoding.UTF8); var filePath2 = System.IO.Path.Combine(AppDomain.CurrentDomain.SetupInformation.ApplicationBase, $"{Guid.NewGuid():N}.txt"); File.WriteAllText(filePath2, "测试 附件 1", Encoding.UTF8); mailMessage.Attachments.Add(MailHelper.CreateAttachment(filePath1)); mailMessage.Attachments.Add(MailHelper.CreateAttachment(filePath2)); MailHelper.SendAsync(mailMessage).GetAwaiter().GetResult(); }