有对snmp协议的详细介绍，同时也有c++源码，有很好的可读性，和学习作用-A detailed descr iption of the snmp protocol, but also a c++ source code, there is very readable, and learning effect

Visual C++案例开发集锦\第九章\SMTP客户端程序的程序源码,值得一看！-Visual C++ case development highlights \ Chapter \ SMTP client' s source code, worth a visit!