MailMessage mail = new MailMessage();
mail.To = "me@mycompany.com";
mail.From = "you@yourcompany.com";
mail.Subject = "this is a test email.";
mail.Body = "this is my test email body";
SmtpMail.SmtpServer = "localhost";  //your real server goes here
SmtpMail.Send( mail );

Dim mail As New MailMessage()
mail.To = "me@mycompany.com"
mail.From = "you@yourcompany.com"
mail.Subject = "this is a test email."
mail.Body = "this is my test email body"
SmtpMail.SmtpServer = "localhost" 'your real server goes here
SmtpMail.Send(mail)

这里的smtpserver只能是那些不需要验证的smtp服务器，像126,sina,yahoo等等的邮箱，都需要验证，所以不能用。用这些邮箱发信后面会讲到


2，发送Html邮件
[ C# ]
 MailMessage mail = new MailMessage();
mail.To = "me@mycompany.com";
mail.From = "you@yourcompany.com";
mail.Subject = "this is a test email.";
mail.BodyFormat = MailFormat.Html;
mail.Body = "this is my test email body.<br><b>this part is in bold</b>";
SmtpMail.SmtpServer = "localhost";  //your real server goes here
SmtpMail.Send( mail );



 [ VB.NET ]
 Dim mail As New MailMessage()
mail.To = "me@mycompany.com"
mail.From = "you@yourcompany.com"
mail.Subject = "this is a test email."
mail.BodyFormat = MailFormat.Html
mail.Body = "this is my test email body.<br><b>this part is in bold</b>"
SmtpMail.SmtpServer = "localhost" 'your real server goes here
SmtpMail.Send(mail)

MailMessage mail = new MailMessage();
mail.To = "me@mycompany.com";
mail.From = "you@yourcompany.com";
mail.Subject = "this is a test email.";
mail.Body = "this is my test email body.";
MailAttachment attachment = new MailAttachment( Server.MapPath( "test.txt" ) ); //create the attachment
mail.Attachments.Add( attachment ); //add the attachment
SmtpMail.SmtpServer = "localhost";  //your real server goes here
SmtpMail.Send( mail );

Dim mail As New MailMessage()
mail.To = "me@mycompany.com"
mail.From = "you@yourcompany.com"
mail.Subject = "this is a test email."
mail.Body = "this is my test email body."
Dim attachment As New MailAttachment(Server.MapPath("test.txt")) 'create the attachment
mail.Attachments.Add(attachment) 'add the attachment
SmtpMail.SmtpServer = "localhost" 'your real server goes here
SmtpMail.Send(mail)


4，修改发件人和收件人的名称
比如发件人的地址是abc@126.com,我们用outlook收到信，From一栏里将直接显示abc@126.com.
能不能在From一栏里显示友好一点的名字呢？
比如显示Tony Gong

方法如下：
[ C# ]
 MailMessage mail = new MailMessage();
mail.To = "\"John\" <me@mycompany.com>";
mail.From = "\"Tony Gong\" <you@yourcompany.com>";
mail.Subject = "this is a test email.";
mail.Body = "this is my test email body.";
SmtpMail.SmtpServer = "localhost";  //your real server goes here
SmtpMail.Send( mail );



 [ VB.NET ]
 Dim mail As New MailMessage()
mail.To = """John"" <me@mycompany.com>"
mail.From = """Tony Gong"" <you@yourcompany.com>"
mail.Subject = "this is a test email."
mail.Body = "this is my test email body."
SmtpMail.SmtpServer = "localhost" 'your real server goes here
SmtpMail.Send(mail)

MailMessage mail = new MailMessage();
mail.To = "me@mycompany.com;him@hiscompany.com;her@hercompany.com";
mail.From = "you@yourcompany.com";
mail.Subject = "this is a test email.";
mail.Body = "this is my test email body.";
SmtpMail.SmtpServer = "localhost";  //your real server goes here
SmtpMail.Send( mail );

Dim mail As New MailMessage()
mail.To = "me@mycompany.com;him@hiscompany.com;her@hercompany.com"
mail.From = "you@yourcompany.com"
mail.Subject = "this is a test email."
mail.Body = "this is my test email body."
SmtpMail.SmtpServer = "localhost" 'your real server goes here
SmtpMail.Send(mail)

 MailMessage mail = new MailMessage();
 mail.To = "me@mycompany.com";
 mail.From = "abc@126.com";
 mail.Subject = "this is a test email.";
 mail.Body = "Some text goes here";
 mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1"); //basic authentication
 mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", "abc"); //set your username here
 mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", "your password"); //set your password here

 SmtpMail.SmtpServer = "smtp.126.com";  //your real server goes here
 SmtpMail.Send( mail );

   Dim mail As New MailMessage()
   mail.To = "me@mycompany.com"
   mail.From = "abc@126.com"
   mail.Subject = "this is a test email."
   mail.Body = "Some text goes here"
   mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1") 'basic authentication
   mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", "abc") 'set your username here
   mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", "Your Password") 'set your password here
   SmtpMail.SmtpServer = "smtp.126.com" 'your real server goes here
   SmtpMail.Send(mail)



7,修改smtp服务器的端口，以及使用SSL加密
大部分smtp服务器的端口是25，但有些却不是
同时，绝大部分Smtp服务器不需要SSL登陆，有些却需要
比如Gmail，smtp端口是：465，同时支持SSL
代码如下：

[ C# ]
 
 MailMessage mail = new MailMessage();
 mail.To = "me@mycompany.com";
 mail.From = "abc@126.com";
 mail.Subject = "this is a test email.";
 mail.Body = "Some text goes here";
 mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1"); //basic authentication
 mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", "abc"); //set your username here
 mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", "your password"); //set your password here
 
 mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpserverport",465);
 mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpusessl", "true");

 SmtpMail.SmtpServer = "smtp.126.com";  //your real server goes here
 SmtpMail.Send( mail );








 [ VB.NET ]
 

   Dim mail As New MailMessage()
   mail.To = "me@mycompany.com"
   mail.From = "abc@126.com"
   mail.Subject = "this is a test email."
   mail.Body = "Some text goes here"
   mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate", "1") 'basic authentication
   mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendusername", "abc") 'set your username here
   mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/sendpassword", "Your Password") 'set your password here
   
   mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpserverport",465)
   mail.Fields.Add("http://schemas.microsoft.com/cdo/configuration/smtpusessl", "true")

   SmtpMail.SmtpServer = "smtp.126.com" 'your real server goes here
   SmtpMail.Send(mail)