发送和接收电子邮件，对于某些执行特殊任务的应用程序而言，是一个十分有用的功能。例如，一个监视网络服务器资源使用情况的工具软件，如果它具有自动发送电子邮件的功能，那么当它发现服务器的资源使用已经接近事先设定的临界状态时，便可以向系统管理员发送一封告警的电子邮件，从而使系统管理员能够及时地采取措施，以避免重大事故的出现。在Visual Basic中，应用程序可以通过调用微软公司的MAPI（Messaging Application Programming Interface，消息应用程序编程接口），实现收发电子邮件的功能。(Sending and receiving e-mail is a very useful function for some applications that perform special tasks. For example, a tool software that monitors the use of a network server resource, if it has the ability to automatically send e-mail, can send an alarm email to the system administrator when it finds that the server's resources are already near the pre set critical state, so that the system administrator can be sent to the system administrator. Take timely measures to avoid major accidents. In Visual Basic, the application can implement the function of sending and receiving e-mail by calling the Microsoft Corp's MAPI (Messaging Application Programming Interface, the message application programming interface).)