Postfix Mail Server: is one of most used server on the internet. There are 3 main components of mail system.
Mail User Agent (MUA): MUA or mail client is used to read, write & send email messages ie it is used to send/receive messages to/from MTA (Mail Transfer Agent). evolution, thunderbird, pine, mutt, mail, outlook express, MS outlook are most common mail user agents.
Mail Transfer Agent (MTA): is used to transfer messages from one system to another on local network or to remote systems over the internet. once configured, users will have no direct interaction with MTA. the most popular are sendmail, postfix, qmail, exim, MS exchange server.
Mail Delivery Agent (MDA): This is generally not visible to users. It runs in background & performs filtering on email messages between MTA & MUA. Most widely used MDAs are Procmail & Spamassassin. The most important usage of these is to remove spam before delivering mail to user mail boxes.
The 3 main protocols used for implementing Mail Server
Simple Mail Transfer Protocol (SMTP): The main purpose of smtp is to transfer mail between mail servers. MUA will send the mail to outgoing mail server, which will deliver to another mail server & so on & finally to destination mail server. so whenever we are configuring mail clients, we need to specify smtp server.
Post Office Protocol (POP): Email clients will download the messages & delete the messages from the server until specified otherwise.
Internet Messaging Application Protocol (IMAP): Messages remain on server. Mail clients can read, delete messages. Mails can be organized/managed on the server.
We will be covering the following topics in this tutorial.
– Implement Postfix Server
– Implement Dovecot Server
– Setting up DNS for Mail Server
– Use of Outlook Express & Evolution
– Access Control Implementation