Linux Network Service 07--postfix mail system

Linux Network services --Postfix mail System (i) a , Messaging System Overview

1.MTA(mail Transferagent) Mail Transfer agent

commonly referred to as mail server software. the MTA software is responsible for receiving messages sent by the client software and transferring the messages to other MTA programs, which are a core part of the e-mail system. Common MTA Software has the Windows system for Exchange and Linux Sendmail,Postfix , etc. under the system .

2,MUA(Mail user agent) mail users Agent

commonly referred to as mail client software. MUAsoftware features provide users with an interface for sending, receiving, and managing e-mail. In theWindowscommon in the platformMUASoftware includesOutlook Express,Outlook,Foxmailand so on. In theLinuxcommon in the platformMUASoftware includesThunderbird,Kmail,Evolutionand so on.

3,MDA(mail Deliveryagent) mail Distribution Agent

The MDA software is responsible for distributing messages to the user's mailbox directory in the server. MDA software is relatively special, it does not directly face the mail user, but the background silently work. Sometimes The MDA function can be directly integrated in the MTA software, so it is often ignored.

two , Mail Communication Protocol

1.SMTP(Simple MailTransfer Protocol) Easy message Transfer Protocol

The SMTP protocol uses the TCP port number

used primarily for sending and transmitting messages. the MUA uses the SMTP protocol to send messages to the MTA Server, and the MTA transmits the messages to other MTA server is also used SMTP agreement.

2.POP(Post Office Protocol) Post Office Protocol

The TCP port number used by the POP3 protocol is

primarily used to collect mail from the mail server. Currently , the latest version of the POP protocol is POP3.

3.IMAP(internetMessage Access Protocol) Internet Messaging Access Protocol

The TCP port number used by the IMAP4 protocol is 143

with the POP is also used to receive mail, compared to the IMAP4 Protocol provides more flexible and powerful mail collection, mail management functions. The current version of the IMAP protocol is IMAP4.

iii. Common mail server Software

1. Commercial mail system:Exchange,notes/domino , etc.

2,unix/linux:Sendmail,Qmail,Postfix wait

The Postfix is developed by Wietse and is designed to provide a better alternative to Sendmail. Postfix has a remarkable performance in delivery efficiency, stability, service performance and safety.

Four ,Postfix compiled installation and service control

1.Postfix mail Server overview

The Postfix Mail server uses a modular design, which is made up of a number of different programs that are used to implement different functions. Postfix starts with a process called master , which is handled by the master process, and automatically load other programs as needed to work together.

2. Compile and install and service control

Official website:http://crushlinux.postfix.org

SOURCE Package postfix-2.11.7.tar.gz

(1) compile and install

1> Environment Preparation

Configuration DNS Domain Name resolution server (detailed process, configuration list below)

Set the default DNS Server

Uninstalling the system default installation of Postfix

Confirm The installation package required for Cyrus certification

2> confirm postfix Mail Service installation required users and groups (if you have previously installed postfix, there is no need to establish)

if the above groups and users do not exist, they must be established in advance .

[Email protected] ~]# groupadd-g Postdrop

[Email protected] ~]# groupadd-g postfix

[Email protected] ~]# useradd-m-u 1000-g postfix-g postdrop-s/sbin/nologin postfix

Source Package Installation Postfix

Where: Compilation parameters The roles of Ccargs and auxlibs are as follows:

Ccargs: Provides additional extension parameters for the compiler, for example: Enable SASL authentication. and refers to the CYRUS_SASL certification program's header file located in /USR/INCLUDE/SASL

Auxlibs: indicates to the compiler that an additional library of functions is located outside of the standard location.

[email protected]mail postfix-2.11.7]# make makefiles ' Ccargs=-duse_sasl_auth-duse_ Cyrus_sasl-i/usr/include/sasl ' AUXLIBS=-L/USR/LIB64/SASL2-LSASL2 ' && make && make install

View The authentication methods supported by the Postfix service

Start the service and view

2> main directory:

/etc/postfix: Includes The main configuration file of Postfix service, various kinds of scripts, query tables, etc.

/usr/libexec/postfix/: each server program file including the Postfix service

/var/spool/postfix/: Includes sub-directories related to the mail queue of the postfix Service, each team list directory because of the different messages saved

Incoming(incoming): Store the message you just received

Active(Active): Store messages that are being posted

Deferred(deferred): Store messages that failed to post previously

hold (Constraint): Stores messages that are blocked from being sent

Corrupt(Error): Storing unreadable or non-parsed messages

/usr/sbin/: Includes Various administrative tools for the Postfix service, these program file names begin with post

Postalias: Constructing, modifying, and querying alias tables

postconf: Displaying and editing the main.cf configuration file

Postfix: Start, stop Postfix Mail Service, require root user Rights

Postmap: Constructs, modifies, or queries a table file (a file that records mappings such as aliases)

Postqueue: View message queues, which are also available to general users

Postsuper: Managing message queues, requiring root user Rights

/usr/sbin/post*: Execute script

/var/log/maillog: Log file

3> Thin mail.conf Configuration Items

postconf: View all currently enabled configurations

Postconf-n: List only configurations that use non-default values

Add Manually:

Inet_interfaces = 192.168.6.106, 127.0.0.1// Listening service IP, default is all

Myhostname = host name of mail.benet.com//mail server

MyDomain = benet.com// mail domain

Myorigin = mail field in the sender's address when $mydomain//outgoing messages

Mydestination = $mydomain, $myhostname// Allow Posting to local destination mail domain

Home_mailbox = maildir/// Set message storage location and format

4> Test

Add Mail user account

send a message test using SMTP source code

To see if the message was sent successfully

Five , Configuration Pop/imap receiving service

1.dovecot receiving service Overview

Pop3/imap Server Software, the impact of fast and good scalability. dovecot By default also uses Linux system users, and through the PAM mechanism for identity authentication, Users are allowed to receive mail only after they have passed the certification.

2. Compile and install the dovecot Package dovecot-2.0.21.tar.gz

1> Create service run user

[Email protected] ~]# useradd-m-s/sbin/nologin dovecot

[Email protected] ~]# useradd-m-s/sbin/nologin dovenull

2> Source Package compilation Installation

Create a configuration file and start the service

Add PAM Authentication Function

start the dovecot service

POP3 receiving mail test

Use Outlook Beta

Tools -Account Settings-new-Manually configure server settings or other server types

Linux Network Service 07--postfix mail system