发送邮件时为何会出现“邮件无法发送到 SMTP 服务器。传输错误代码为 0x800ccc15。服务器响应为 not available ”

[ristona]

我用的是SMTPMAIL类

[starheart]

这样试一试：把设置SMTP的那一句代码去掉，使用系统的默认设置，

[tjq_tang]

//不知道这个能不能对你有所帮助
MailMessage mail = new MailMessage();
mail.To = "[e-mail]";
mail.From = "[e-mail]";
mail.Subject = "this is a test email.";
mail.Body = "Some text goes here";
mail.Attachments.Add (new MailAttachment("c:\\test.txt"));
mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1"); //basic authentication
mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", "tjq_tang"); //set your username here
mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", "qqq"); //set your password here

SmtpMail.SmtpServer = "smtp.tom.com"; //your real server goes here
SmtpMail.Send( mail );
MessageBox.Show("发送成功");