当reciepent有错误的电子邮件地址时，Smtp.Send不会抛出任何错误

I am sending email using SmtpClient.Send Method, but when I try to send to a non-existent email account, the Send method throws no exception, how can I tell that the recipient mail address is valid, or the mail won't arrive, or detect this issue.

我使用SmtpClient.Send方法发送电子邮件，但是当我尝试发送到不存在的电子邮件帐户时，Send方法不会抛出任何异常，如何判断收件人邮件地址是有效的，还是邮件不会到达，或检测到这个问题。

code:

码：

            Properties.Settings appSettings = new Properties.Settings();
            MailMessage message = new MailMessage();

            message.From = new MailAddress(appSettings.senderMail);        
            message.Subject = appSettings.mailsubj;
            message.Body = appSettings.mailbody;
            Attachment attach = new Attachment(sOutput);
            message.Attachments.Add(attach);

            SmtpClient client = new SmtpClient(appSettings.SMTP);

            client.SendCompleted += this.SendCompletedCallback;
            foreach (String clientEmail in clientEmailList)
            {
                message.To.Clear();
                message.To.Add(clientEmail);
                //client.Send(message);

                try
                {
                    client.Send(message);
                    AddToLog(String.Format("\t{0}{1}", Properties.Resources.ResourceManager.GetString("MAIL_SEND_SUCCESS"), clientEmail));
                }
                catch (SmtpFailedRecipientException ex)
                {
                    AddToLog(String.Format("\t{0}{1}:\n\t{2}", Properties.Resources.ResourceManager.GetString("MAIL_SEND_ERROR"), clientEmail, ex.Message));
                }
                catch (SmtpException smtp_Ex)
                {
                    AddToLog(String.Format("\t{0}{1}:\t{2}", Properties.Resources.ResourceManager.GetString("MAIL_SEND_ERROR"), clientEmail, "Cannot connect to SMTP server."));
                }
                catch (Exception ex)
                {
                    AddToLog(String.Format("\t{0}{1}:\n\t{2}", Properties.Resources.ResourceManager.GetString("MAIL_SEND_ERROR"), clientEmail, ex.Message));
                }
              //  client.SendAsync(message, clientEmail);
            }

1 个解决方案

#1

When SMTP client sends a message, it doesn't know anything about validity of e-mail address, if this address belongs to the domain, that differs from SMTP server's domain.

当SMTP客户端发送邮件时，它不知道电子邮件地址的有效性，如果该地址属于域，则与SMTP服务器的域不同。

This will be known only after your SMTP server will try to deliver a message to the recipient from another domain. Usually, in this case you'll receive a mail message with error.

只有在您的SMTP服务器尝试从其他域向收件人传递邮件后，才能知道此情况。通常，在这种情况下，您将收到包含错误的邮件。

#1