linux[Basic]-35-[Post Office System]-[postfix and DOVECOT]-[01]

Postfix and Devecot Sending and receiving mail

The Mail Application protocol includes:

a Simple Mail Transfer Protocol ( SMTP): Used to send or relay e-mail,port:

Third edition Post Office Protocol ( POP3): Used to store messages on the server to the local host,port:

Fourth edition Internet Information Access Protocol ( IMAP4), which is used to access Mail on localhost,port:143

The e-mail system consists of three parts:

User Agent MUA: For sending and receiving mail

Mail Transfer Agent MTA: Forward messages from MUA to a specified user

Mail Delivery Agent MDA: Saving messages from the MTA to your native inbox

e-mail systems are fundamentally different from most network application protocols:

FTP Service: Both communication must be online at the same time, otherwise it will error the connection timeout

e-mail system: If the other party's server down, will temporarily store the message locally, detected the other side of the server to complete the delivery

Enterprise-Class E-mail:

Anti-spam anti-virus module: prevent spam or virus messages from interfering with corporate mailboxes

Message encryption: Ensure message content is not sniffed, tampered with

e-Mail monitoring audit: monitor all staff in the e-mail messages are not sensitive words, disclose enterprise information, etc.

Stability: Good resistance to DDOS attack capability to ensure system reliability

Deploying a basic e-mail system requires:

Postfix: Mail Send (SMTP)

Dovecot: Mail acceptance (POP3)

Outlook: Client mail sending and receiving

Simulation Experiment:

Environment :

DNS Server	Rhel7	IP:192.168.200.102
Mail server	Rhel7	IP:192.168.200.103
Client	Windows 7	IP:192.168.200.200

DNS server configuration:

[Email protected] ~]# yum-y install bind bind-Chroot[[email protected]~]# vim/etc/named.conf//Modify the Listening port IP on line 11Listen-on Port -{192.168.200.102; };//Modify the 17 row to allow the queried host to be any Allow-query {any;}; [[Email protected]~]# vim/etc/Named.rfc1912.zoneszone"linuxs.com"In {type master; File"Linuxs.com.zone"; allow-update {none;};}; [[Email protected]~]# CD/var/named/[email protected] named]# CP-a named.localhost linuxs.com.zone[[email protected] named]# vim Linuxs.com.zone$ttl 1d@ in SOA linuxs.com. Linu Xs.com. (0; serial 1D; Refresh 1H ; Retry 1W; Expire 3H); Minimum NS ns1.linuxs.com.@ in MXTenmail.linuxs.com.ns1 A192.168.200.102Mail A192.168.200.103[[email protected] named]# systemctl restart Named[[email protected] named]# systemctl enable NAMEDLN-S'/usr/lib/systemd/system/named.service' '/etc/systemd/system/multi-user.target.wants/named.service'

To configure the mail server:

" mail.linuxs.com " >/etc/~~]# yum-y install postfix dovecot

the configuration file for the Postfix Post Office service program is as follows:

File	Role
/usr/sbin/postfix	Main Service Program
/etc/postfix/master.cf	configuration file for master main program
/etc/postfix/main.cf	configuration files for postfix services
/var/log/maillog	Logging the message delivery process

to view The main configuration file for the Postfix service program:

[Email protected] ~]# CAT/ETC/POSTFIX/MAIN.CF

Parameters	Role
Myhostname	Host name of the Post Office system
MyDomain	The domain name of the Post Office system
Myorigin	The domain name of the message sent from this computer
Inet_interfaces	Nic Interface for monitoring
Mydestination	Host name or domain name that can receive mail
Mynetworks	Set up messages for which hosts can be forwarded
Relay_domains	Set which domains can be forwarded for mail

To modify the parameters of the Postfix master configuration file:

[Email protected] ~]# vim/etc/postfix/main.cf//Modify the postoffice host name on line 76thMyhostname=mail.linuxs.com//Modify the Post office domain name on line 83rdmydomain=linuxs.com//Modify the outgoing mail domain name for line 99th ($mydomain already defined in 83 rows)Myorigin=$mydomain//Modify the Listening network card on line 116thinet_interfaces= All//Modify the host name and domain name of the incoming message on line 164thmydestination=$myhostname, $mydomain

Create a Post office account :

[Email protected] ~"123.com" | passwd--stdin Boss

To start the postfix program:

[Email protected] ~~]# systemctl enable Postfix

To modify the Dovecot program master configuration file:

[Email protected] ~]# vim/etc/dovecot/dovecot.conf// Modify the Post Office Protocol on Line 24th (and append allow clear text authentication)=  = no// Modify line 48th allows login to the network segment address (all allowed for 0.0.0.0/0)192.168. 200.0/

To configure the format and storage path for messages:

[[email protected] ~]# vim/etc/dovecot/conf.d/-mail.conf// Remove The 25-line Comment = mbox:~/mail:inbox=/var/mail/%u

To create a storage directory for the message:

[email protected] ~]# Su-~]$ mkdir-p Mail/.imap/inbox

To start the Dovecot program:

[Email protected] ~~'/usr/lib/systemd/system/dovecot.service'  /etc/systemd/system/multi-user.target.wants/dovecot.service'

Windows7 Outlook Verification :

Root user received mail:

　　

To set up a user alias mailbox:

[Email protected] ~]# vim/etc/aliasesxxoo:           ~]# newaliases

Verify:

Root user received mail:

linux[Basic]-35-[Post Office System]-[postfix and DOVECOT]-[01]