The SmtpMail class can be used to send from your C# application. Mail is by default queued on the system, ensuring that the calling program does not block network traffic. The SmtpMail class is defined in the namespace System.Web.Util. You need to call
using System.Web.Util
before you use SmtpMail. This class has only one member function Send. Send sends a mail message. The Send method is overloaded. Either a MailMessage class or four arguments can be passed to the Send message. You can call the Send method in two manners:
The MailMessage Class
The MailMessage class can be used to send mails with cc, bcc or attachments. The MailMessage constructor initializes a new instance of the MailMessage class. It doesn't take any parameters.