This is a really simple one, but I have seen a lot of people asking so I thought I'd write a quick tip for it.
A lot of people will advise you to create an instance of System.Web.Mail.MailMessage and then send it using System.Web.Mail.SmtpServer, but there is a much more simple way.
System.Web.Mail has a class SmtpMail. This class has a static method named "Send". To send an email it is as simple as doing this...
System.Web.Mail.SmtpMail.Send(to, from, subject, body);