C#发送Email邮件（实例：QQ邮箱和Gmail邮箱）

下面用到的邮件账号和密码都不是真实的，需要测试就换成自己的邮件账号。

需要引用：
using System.Net.Mail;
using System.Text;
using System.Net;

程序代码：

        MailMessage myMail = new MailMessage(); //创建邮件实例对象

        myMail.From = new MailAddress(""); //发送者，要和邮件服务器的验证信息对应，不能随便更改

        myMail.To.Add(new MailAddress("")); //接收者

        myMail.Subject = "C#发送Email"; //邮件标题
        myMail.SubjectEncoding = Encoding.UTF8; //标题编码

        myMail.Body = "this is a test email!"; //邮件内容
        myMail.BodyEncoding = Encoding.UTF8; //邮件内容编码
        myMail.IsBodyHtml = true;     //邮件内容是否支持html

        SmtpClient smtp = new SmtpClient(); //创建smtp实例对象
        smtp.Host = "mail.sina.com"; //邮件服务器SMTP
        smtp.Port = 25;                  //邮件服务器端口
        smtp.Credentials = new NetworkCredential("", "123456"); //邮件服务器验证信息

        smtp.Send(myMail); //发送邮件

使用Gmail邮箱发送邮件示例

        MailMessage myMail = new MailMessage();

        myMail.From = new MailAddress("");
        myMail.To.Add(new MailAddress(""));

        myMail.Subject = "C#发送Email";
        myMail.SubjectEncoding = Encoding.UTF8;

        myMail.Body = "this is a test email from gmail!<a href='http://www.sina.com.cn'>sina</a>";
        myMail.BodyEncoding = Encoding.UTF8;
        myMail.IsBodyHtml = true;

        SmtpClient smtp = new SmtpClient();
        smtp.Host = "smtp.gmail.com";
        smtp.Port = 587; //Gmail的smtp端口
        smtp.Credentials = new NetworkCredential("", "123456");
        smtp.EnableSsl = true; //Gmail要求SSL连接

        smtp.DeliveryMethod = SmtpDeliveryMethod.Network; //Gmail的发送方式是通过网络的方式，需要指定

        smtp.Send(myMail);

使用QQ邮箱发送邮件示例

        MailMessage myMail = new MailMessage();

        myMail.From = new MailAddress("");
        myMail.To.Add(new MailAddress(""));

        myMail.Subject = "C#发送Email";
        myMail.SubjectEncoding = Encoding.UTF8;

        myMail.Body = "this is a test email from QQ!";
        myMail.BodyEncoding = Encoding.UTF8;
        myMail.IsBodyHtml = true;

        SmtpClient smtp = new SmtpClient();
        smtp.Host = "smtp.qq.com";
        smtp.Credentials = new NetworkCredential("", "123456");

        smtp.Send(myMail);