pop smtp

发邮件 smtp协议 Simple Mail Transfer Protocol
http://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol

RFC 5321 –
The Simple Mail Transfer Protocol (obsoletes RFC
821 aka STD 10, RFC
974, RFC
1869, RFC
2821)
发送附件
多用途互联网邮件扩展（MIME，Multipurpose Internet Mail Extensions）是一个互联网标准，它扩展了电子邮件标准，使其能够支持非ASCII字符、二进制格式附件等多种格式的邮件消息。这个标准被定义在RFC
2045、RFC 2046、RFC 2047、RFC
2048、RFC 2049等RFC中。

http://blog.csdn.net/kuzuozhou/article/details/7339362
http://blog.csdn.net/helihui123/article/details/6705041  (发送附件)

RFC
5321 简体中文版[1] - Google Docs

收邮件 pop协议 POST OFFICE PROTOCOL
http://en.wikipedia.org/wiki/Post_Office_Protocol

RFC 5034 –
The Post Office Protocol (POP3) Simple Authentication and Security Layer (SASL) Authentication Mechanism
http://blog.csdn.net/agoago_2009/article/details/7265709
http://net.it168.com/app/2007-06-27/20070627113601.shtml