c# – Office 365 SMTP开始触发net_io_connectionclosed

System.IO.IOException: Unable to read data from the transport connection: net_io_connectionclosed. 
at System.Net.Mail.SmtpReplyReaderFactory.ProcessRead(Byte[] buffer, Int32 offset, Int32 read, Boolean readLine) 
at System.Net.Mail.SmtpReplyReaderFactory.ReadLines(SmtpReplyReader caller, Boolean oneLine) 
at System.Net.Mail.SmtpReplyReaderFactory.ReadLine(SmtpReplyReader caller) 
at System.Net.Mail.CheckCommand.Send(SmtpConnection conn, String& response) 
at System.Net.Mail.SmtpTransport.SendMail(MailAddress sender, MailAddressCollection recipients, String deliveryNotify, Boolean allowUnicode, SmtpFailedRecipientException& exception) 
at System.Net.Mail.SmtpClient.Send(MailMessage message)

我怎样才能防止这种情况发生？

  MailMessage message = new MailMessage(System.Configuration.ConfigurationManager.AppSettings["smtpfrom"], email, strOnderwerp, strBody);
            message.Priority = MailPriority.Normal;
            message.IsBodyHtml = true;
            SmtpClient client = new SmtpClient(System.Configuration.ConfigurationManager.AppSettings["smtpserver"], Convert.ToInt32((System.Configuration.ConfigurationManager.AppSettings["smtpport"])));

            client.EnableSsl = Boolean.Parse(System.Configuration.ConfigurationManager.AppSettings["smtpssl"]); ;
            client.Credentials = new System.Net.NetworkCredential(System.Configuration.ConfigurationManager.AppSettings["smtpuser"], System.Configuration.ConfigurationManager.AppSettings["smtppass"]);

            client.Send(message);
            client.Dispose();

Dispose上似乎抛出异常.

我认为解决问题的方法是更改​​SMTP服务器地址.

我们原来的SMTP服务器地址是podxxxxx.outlook.com,大部分时间仍然有效.我在门户网站上检查了当前的O365 SMTP服务器地址,它应该是smtp.office365.com.

我改变了我的配置指向这个新地址,问题似乎消失了.我的日志显示更改后的最后24小时没有错误.

如果错误再次发生,我会更新.