I want make a mail server, but I do't know how it works.
I already installed one in windows but I still dont't understanding how works a mail server.
I need a registry domain in web?
I can create more accounts (emails addresses) that those I have in my web domain?
How I configure the server to send emails to my web domain (server)?
How I configure the mail client to receive the mails from server?
The connection with the outside of my lan is made from ip address (like apache) or i use my domain (www.helderraposo.net)?
Did I need any data of my domain server?

Read documentation about mail server programs, like dovecot or sendmail or postfix. And about configuring them. That should answer to many of your questions, if you just read carefully, trying to understand each thing (and not just "read them in less than a minute").

A mail server is basically a program that deals with text data which is understood as "mail". Creating a connection between two such programs requires some configuration on both ends, but you should figure out by visiting the websites of the programs I mentioned above (and more) and reading the documentation, manuals, FAQs etc. there.

Please don't double post. http://www.linuxquestions.org/questi...d.php?t=488049

Please post your thread in only one forum. Posting a single thread in the most relevant forum will make it easier for members to help you and will keep the discussion in one place. This thread is being closed because it is a duplicate.