What are the function of mail server?

Answer 1

A mail server (also known as a mail transfer agent or MTA, a mail transport agent, a mail router or an internet mailer) is an application that receives incoming e-mail from local users (people within the same domain) and remote senders and forwards outgoing e-mail for delivery.

The mail server functions in conjunction with some other programs to create up what exactly is occasionally known to as a messaging system. A messaging system consists of all the programs required to maintain e-mail moving as it ought to. Whenever you send out an e-mail message, your own e-mail program, for example Outlook or Eudora, forwards the message to your mail server, which often forwards it either to another mail server or to a holding area on the same server known as a message store to become forwarded later. As a rule, the system uses SMTP (Simple Mail Transfer Protocol) or ESMTP (extended SMTP) for sending e-mail, and either POP3 (Post Office Protocol 3) or IMAP (Internet Message Access Protocol) for receiving e-mail.