Quote:
Originally Posted by
kypeswith
i could manage in c++ possibly.. with some guidance but i'm trying to learn some shell programming
Remember "horses for courses", the SMTP protocol used between servers on port 25 is a protocol that requires responses based on logic and state. Shell script is not the language for trying to do this in this situation. You would have better success with C, C++, Java, Perl or Python.
SMTP is an open protocol and you are welcome to use it, as all mail-transfer-agents do.
Also, consider why are you trying to re-invent the wheel, projects such as postfix do an excellent job of managing SMTP both outgoing and incoming in a very flexible manner, allowing you to concentrate on what you are trying to do rather than the nitty-gritties of the SMTP protocol.