Mail server (i)--How the mail server works

Basic concept of mail server:

1. Mail Transfer Protocol

Smtp:simple Mail Transfer Protocol

Pop3:post Office Protocol

Imap4:internet Mail Access Protocol

2.SMTPD Monitoring (25/TCP)

3.sasl:simple Authentication Secure Layer

Cyrus-sasl

Courier-authlib

4.MDA: Mail delivery agent, MDA is hanging under the MUA of a small function, its main function is to analyze the message header, determine the message to go

Procmail,maildrop

5.MUA: Mail user agent, the mail client software, such as Outlook for Windows, through which customers browse, write, and receive mail

Mutt (Text interface), mail,thunderbird,evolution

6.MTA: Mail transfer agent, when you dots a message on a MUA (such as Outlook), it is actually sending the message to the MTA (such as SendMail, Postfix) and the ability to send mail via the MTA

Sendmail,qmai,postfix,exim

7.MRA: Mail Retrieval Agent (POP3,IMAP4), MUA send request to MRA to receive mail

Cyrus-imap

Dovecot

Mail server (i)--How the mail server works