发送邮件

using System.Net.Mail;//使用该命名空间
public void button1_onclick(object sender EventArgs e)
{
//Message 对应：发件人地址，接收邮件地址，邮件的标题，邮件的内容
   MailMessage myMail = new MailMessage(TextBox2.Text.Trim(), TextBox1.Text.Trim(), TextBox4.Text.Trim(), TextBox5.Text.Trim());
//设置邮箱的优先级
        myMail.Priority = MailPriority.High;
//SMTP协议    服务器，和端口号
        SmtpClient client = new SmtpClient("smtp.163.com", 25);
//密码校验
        client.Credentials = new System.Net.NetworkCredential(TextBox2.Text.Trim(), TextBox3.Text.Trim());
//发送
        client.Send(myMail);

}