关于QQ邮箱“命令顺序不正确。 服务器响应为:Error: need EHLO and AUTH first !”问题

1、首先在QQ邮箱当中开启“POP3/SMTP服务”

 

.2、获取“授权码

 

刚开始一直使用邮箱的密码。后面才发现，原来QQ邮箱通过第三方发送邮件应该使用授权码 o(≧口≦)o

附上腾讯的说明http://service.mail.qq.com/cgi-bin/help?subtype=1&&no=1001256&&id=28

 

3、编码

使用SmtpClient来解决

EnableSsl设置为true

UseDefaultCredentials设置为false

Credentials = new System.Net.NetworkCredential("QQ邮箱", "授权码");

附上代码，做个备忘

 

public static void Send(Email mail,string email)
        {
            SmtpClient client = new SmtpClient("smtp.qq.com");
            client.EnableSsl = true;
            client.UseDefaultCredentials = false;
            client.Credentials = new System.Net.NetworkCredential("QQ邮箱", "授权码");

            MailAddress from = new MailAddress("QQ邮箱", "显示名称", Encoding.UTF8);//初始化发件人

            MailAddress to = new MailAddress(email, "", Encoding.UTF8);//初始化收件人

            //设置邮件内容
            MailMessage message = new MailMessage(from, to);
            message.Body = mail.Body;
            message.BodyEncoding = mail.BodyEncoding;
            message.Subject = mail.Subject;
            message.SubjectEncoding = mail.SubjectEncoding;
            message.IsBodyHtml = mail.IsBodyHtml;

            //发送邮件
            try
            {
                client.Send(message);
            }
            catch (InvalidOperationException iex)
            { }
            catch (Exception ex)
            { }
        }

注意：一定要先设置 EnableSsl和UseDefaultCredentials，再实例化Credentials