c# - SmtpClient: 连接尝试失败，因为连接方在一段时间后没有正确响应

Question

在 visual studio 2008 中使用 C#.NET 发送电子邮件时出现以下错误

A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 74.125.53.108:25

但是相同的代码在其他一些 PC 上工作正常，但是当我今天测试时，它在 Send() 方法中给我错误...而且我的网络连接很好，我正在测试电子邮件代码..

下面是我的邮箱代码

MailMessage mail = new MailMessage();
mail.To.Add(to);
mail.From = new MailAddress(from);
mail.Subject = subject;
mail.Body = body;
mail.IsBodyHtml = true;
SmtpClient smtp = new SmtpClient();
smtp.Host = "smtp.gmail.com";
smtp.Credentials = new System.Net.NetworkCredential("MyUserName@gmail.com",
                                                            "MyPassword");
smtp.EnableSsl = true;
smtp.Send(mail);

这种错误的原因可能是什么..？？？

Answer 1

以下代码适用于我。你的代码给我错误，我相信这是因为没有将端口设置为 587。

http://forums.asp.net/t/1250771.aspx/4/10

MailMessage mail = new MailMessage();
mail.To.Add(to);
mail.From = new MailAddress(from);
mail.Subject = subject;
mail.Body = body;
mail.IsBodyHtml = true;
SmtpClient smtp = new SmtpClient("smtp.gmail.com",587);
smtp.EnableSsl = true;
smtp.UseDefaultCredentials = false;
smtp.Credentials = new System.Net.NetworkCredential(address, password);
smtp.Send(mail);