E-Mail play a very important role in modern times.More and more people are using it,and the number of it will larger and larger.Though there are a lot of software for sending and receiving letters such as FoxMail which are also multifunctional,it is difficult and complicated to the Most of people who are curbstone.For this reason,we do this software with the rock-bottom protocol of SMTP and Pop. The full name of SMTP is Simple Mail Transfer Protocol.It is Used to sending letters.The full name of Pop is Post Office Protocol which is Special to receive letters.I basically take charge to how to realize the function of sending letters. A namespace which is named MailSend is the soul of my programe.It includes two classes.A method named sendmial which realize the fuction step by step belongs to the class of SmtpMail. It detailedly note the track of client exchange to the server. You can use the software to send either a text E –Mail or a textE-mail with Attachments.You also can Send a letter to many addressee. In the nature of things,you can use a different SMTP service. The software I did support multiletters and multisender after I test.It is simplier than FoxMail and other professional softwares,but it is easy to hold and use.