Shulou(Shulou.com)06/02 Report--

Last time we looked at the basics of the mail service family, this time we'll look at the components required for each agent and the postfix installation process.

Open Source MTA (Mail Transfer Agent) Three Musketeers:

sendmail: UUCP monomer structure, all functions are implemented using a process, any process is at risk, the entire server is affected, and SUID is used, so the whole process is relatively insecure, and the configuration file syntax is written using M4, which is difficult to master.

qmail: good performance but failed in later development, only used by a few enterprises

postfix: modular design, each function is implemented using a module, not suitable for M4 writing; relatively safe, root sendmail compatibility is good, delivery efficiency is more than four times that of sendmail, so many systems use postfix

exim: from Cambridge University, UK, simple grammar, easy to use

Exhcange: can only be installed in windows, but also as an asynchronous messaging collaboration platform.

MDA: Mail Delivery Agent

procmail maildrop

MRA：（pop3,imap4）

cyrus-imap dovecot

MUA (Mail User Agent)

Outlook Express

Foxmail

ThunderBird , Evolution

Plain text interface: mutt!!! We mainly use

webmail mailbox service program

Squirrelmail: Using PHP to develop, Squirrel Mail

SASL: General use v2 version

cyrus-sasl: uses a lot of core components, not just itself

courier-authlib: used for authentication to mysql, more powerful than cyrus-sasl

Next, implement the deployment mail system

Postfix + SASL (MySQL authentication with courier-authlib)+MySQL

DoveCot + MySQL

Exrmail + Extman + httpd

The following demonstrates the installation process on Red Hat 6

The postfix package provided by rpm package cannot meet the requirements of male football virtual user authentication, so it can only be installed through its own source code compilation.

First stop sendmail service, then close sendmail, you can uninstall it directly here, as shown below

There are dependencies in the unloading process, which can be ignored directly.

Before installing postfix, you must install MySQL first, otherwise you cannot authenticate virtual users. It is important to provide installation of header files and library files.

Next, install the postfix

1. Find postfix's site first: www.postfix.com

Select version 2.10.0 here, download the tar.gz file, put it in the ftp source, extract it locally, and then enter the directory to view it. There is no config file in it, so we cannot configure and install it directly in the config file.

2. Install according to the following installation documentation

First you create groups and users as follows

Then make sure that the cyrus-sasl-devel package is installed

3. Next, make, make install Complete the installation of postfix

After installation, specify its installation location, temporary directory, configuration file, command directory, service process, writable file storage location, html directory, mail queue program, manual installation location, generate new alias, mail queue location, readme document, send-mail path, setgid-mailgroup, etc., installation ends

Startup Services:

4. Next, we introduce the postfix configuration file:

master：/etc/postfix/master.cf

mail ：/et/postfix/main.cf

Parameter-Value: Parameter must unload the absolute beginning of a line, a line that begins with a blank is considered a continuation of the previous line

postconf: Configure Postfix

-d: Display default configuration

-n: Modified configuration

-m: Displays all supported lookup table types

-A: Displays supported SASL client plug-in types

-e: Edit the file directly, change the configuration information of a parameter, and save it to the main.cf file

smtp status code:

1XX: Purely descriptive information,

2XX: Correct information

3XX: The previous operation has not been completed, and needs to be supplemented.

4XX: Temporary error

5XX: permanent error

smtp protocol command (primitive)

helo(smtp protocol)

ehlo(esmtp protocol)

mail from: Specify the sender

rcpt to: Specify recipient

A process of sending and receiving emails is shown below. Postfix is successfully installed and can be easily used.

1 The process of sending mail

2. view the log

You can see status=sent, indicating that the mail has been sent successfully.

3. Check mail at destination

Since then, the installation and simple configuration of postfix have been completed, and the email sending of the intranet has been realized, but the email sending to the external network host cannot be realized. Next, the deployment of postfix, sasl and MySQL as a whole system will be completed.

For more information, see the next chapter.

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