C#发送Email邮件（实例：QQ邮箱和Gmail邮箱）

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

一，使用Gmail邮箱发送邮件示例

SmtpClient smtpclient = new SmtpClient();
smtpclient.Host = "smtp.gmail.com";//smtp.163.com smtp.qq.com
smtpclient.Port = 587;//gmail服务器端口

//确定发件地址与收件地址
string senderGmail = "*****@gmail.com";
string receiverGmail = "******@qq.com";
MailAddress sendAddress = new MailAddress(senderGmail);
MailAddress receiveAddress = new MailAddress(receiverGmail);

//构造一个Email的Message对象 内容信息
MailMessage mailMessage = new MailMessage();
mailMessage.Subject = "C#发送Emai"; //邮件标题
mailMessage.SubjectEncoding = Encoding.UTF8;
mailMessage.Body = "测试邮件发送成功。";
mailMessage.BodyEncoding = Encoding.UTF8;
mailMessage.IsBodyHtml = true;

mailMessage.From = sendAddress;
mailMessage.To.Add(receiveAddress);

//邮件发送方式  通过网络发送到smtp服务器
smtpclient.DeliveryMethod = SmtpDeliveryMethod.Network;

//如果服务器支持安全连接，则将安全连接设为true
smtpclient.EnableSsl = true;
    try
    {
        //是否使用默认凭据，若为false，则使用自定义的证书，就是下面的networkCredential实例对象
        smtpclient.UseDefaultCredentials = false;

        //指定邮箱账号和密码,需要注意的是，这个密码是你在QQ邮箱设置里开启服务的时候给你的那个授权码
        NetworkCredential networkCredential = new NetworkCredential(senderGmail, "x1472583690.");
        smtpclient.Credentials = networkCredential;

        //发送邮件
        smtpclient.Send(mailMessage);
        Console.WriteLine("发送邮件成功");
       
    }
    catch (System.Net.Mail.SmtpException ex)
    {
        Console.WriteLine(ex.Message, "发送邮件出错");
    }