>In my project, I want to add a Email function.
>Any apporach to create this module? LAN Email is also ok.

I created a FAQ for that on Internet section.

For the best, you will probably want to use Mailx. This is what I use for distributing 150000 emails per week for all my applications. It also supports VIM, SMTP, POP, file attachment and whatever you'll need. This tool is just fantastic.