Wednesday, 25 October 2017

RHEL7 Mail Server(Postfix)

Mail Server(Postfix)

                 

 

 

Postfix is a powerful but easy-to-configure mail server

 

Postfix is a free and open-source mail transfer agent(MTA)that routes and deliver electronic mail

Postfix implements a high-performance parallelized mail-delivery

engine

Postfix implements a limited number of features in the MTA,and relies on third-party extensions for the rest

 

                Server Configuration

 

To install postfix Mail Server

 

 

[root@server ~]# yum install -y postfix

Loaded plugins: fastestmirror, langpacks

base                                                     | 2.9 kB     00:00

Loading mirror speeds from cached hostfile

Package 2:postfix-2.10.1-6.el7.x86_64 already installed and latest version

Nothing to do

[root@server ~]#

 

 

To Add a smtp service to the firewall:

 

 

[root@server ~]# firewall-cmd --permanent --add-service=smtp

success

[root@server ~]# firewall-cmd --zone=public --permanent --add-port=25/tcp

success

 

 

To Reload the firewall configuration

 

 

[root@server ~]# firewall-cmd --reload

success

 

 

To Activate the postfix service at boot:

 

[root@server ~]# systemctl enable postfix

 

 

 

 

To Start the postfix mail server

 

 

[root@server ~]# systemctl start postfix

 

 

 

To check the status of postfix mail server

 

 

[root@server ~]# systemctl status postfix

? postfix.service - Postfix Mail Transport Agent

  Loaded: loaded (/usr/lib/systemd/system/postfix.service; enabled; vendor preset: disabled)

  Active: active (running) since Mon 2017-10-23 16:47:05 IST; 3min 34s ago

Main PID: 1439 (master)

  CGroup: /system.slice/postfix.service

          ??1439 /usr/libexec/postfix/master -w

          ??1449 pickup -l -t unix -u

          ??1450 qmgr -l -t unix -u

 

Oct 23 16:46:53 server systemd[1]: Starting Postfix Mail Transport Agent...

Oct 23 16:47:05 server postfix/master[1439]: daemon started -- version 2.10.1, configuration /etc/postfix

Oct 23 16:47:05 server systemd[1]: Started Postfix Mail Transport Agent.

 

      

               

Configure a central mail server

               

 

Edit the /etc/postfix/main.cf file and change the following directives:

 

 

[root@server ~]# vi /etc/postfix/main.cf

[root@server ~]#

myhostname = server.agoutam.com

mydomain = agoutam.com

myorigin = $mydomain

inet_interfaces = all

mydestination = $myhostname,localhost.$mydomain,localhost,$mydomain

mynetworks = 192.168.56.0/24,127.0.0.0/8

 

 

 

 

 

To Check the syntax of postfix main configuration file

 

 

[root@server ~]# postfix check

 

 

To Check the non-default configuration :

 

 

[root@server ~]# postconf -n

alias_database = hash:/etc/aliases

alias_maps = hash:/etc/aliases

command_directory = /usr/sbin

config_directory = /etc/postfix

daemon_directory = /usr/libexec/postfix

data_directory = /var/lib/postfix

debug_peer_level = 2

debugger_command = PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin ddd $daemon_                                                          directory/$process_name $process_id & sleep 5

html_directory = no

inet_interfaces = all

inet_protocols = all

mail_owner = postfix

mailq_path = /usr/bin/mailq.postfix

manpage_directory = /usr/share/man

mydestination = $myhostname, localhost.$mydomain, localhost, $mydomainmydomain = agoutam.com

myhostname = server.agoutam.com

mynetworks = 192.168.56.0/24, 127.0.0.0/8

myorigin = $mydomain

newaliases_path = /usr/bin/newaliases.postfix

queue_directory = /var/spool/postfix

readme_directory = /usr/share/doc/postfix-2.10.1/README_FILES

sample_directory = /usr/share/doc/postfix-2.10.1/samples

sendmail_path = /usr/sbin/sendmail.postfix

setgid_group = postdrop

unknown_local_recipient_reject_code = 550

 

 

                             

 

To Set the SELinux boolean to "on":

 

 

[root@server mail]# setsebool -P allow_postfix_local_write_mail_spool on

 

 

To create User to use for mail Service

 

 

[root@server mail]# adduser msgoutam

 [root@server mail]# passwd msgoutam

Changing password for user msgoutam.

New password:

BAD PASSWORD: The password contains the user name in some form

Retype new password:

passwd: all authentication tokens updated successfully.

 

 

To Send mail to user msgoutam

 

 

[root@server mail]# echo testmail |mail -s "Test Mail to Agoutam" msgoutam@agoutam.com

 

 

 

 

To Check Mail account of  user msgoutam

 

 

[root@server mail]# su - msgoutam

[msgoutam@server ~]$ mail

Heirloom Mail version 12.5 7/5/10.  Type ? for help.

"/var/spool/mail/msgoutam": 1 message 1 new

>N  1 root                  Mon Oct 23 17:11  18/591   "Test Mail to Agoutam"

& 1

Message  1:

From root@agoutam.com  Mon Oct 23 17:11:14 2017

Return-Path: <root@agoutam.com>

X-Original-To: msgoutam@agoutam.com

Delivered-To: msgoutam@agoutam.com

Date: Mon, 23 Oct 2017 17:11:14 +0530

To: msgoutam@agoutam.com

Subject: Test Mail to Agoutam

User-Agent: Heirloom mailx 12.5 7/5/10

Content-Type: text/plain; charset=us-ascii

From: root@agoutam.com (root)

Status: R

 

testmail

 

 

 

 

 

 

Type r to Reply to the mail

 

 

& r

To: msgoutam@agoutam.com root@agoutam.com

Subject: Re: Test Mail to Agoutam

 

root@agoutam.com (root) wrote:

 

> testmail

Got mail ,Thanks

 

 

 

Type q to quit from Mail Service

 

& q

New mail has arrived.

Held 1 message in /var/spool/mail/msgoutam

You have mail in /var/spool/mail/msgoutam

[msgoutam@server ~]$ su root

 

 

Configure a Client to forward all email to a central mail server

 

                     Null-client configuration

 

To Install postfix Mail Server in Client machine

 

[root@client ~]# yum install -y postfix

Loaded plugins: fastestmirror, langpacks

base                                                     | 2.9 kB     00:00

Loading mirror speeds from cached hostfile

Package 2:postfix-2.10.1-6.el7.x86_64 already installed and latest version

Nothing to do

[root@client ~]#

 

 

To Add service smtp in firewall

 

 

[root@client ~]# firewall-cmd --permanent --add-service=smtp

success

[root@client ~]# firewall-cmd --zone=public --permanent --add-port=25/tcp

success

 

 

 

To Reload firewall configuration

 

 

[root@client ~]# firewall-cmd --reload

success

 

 

To enable Postfix Mail Server during Boot Time.

 

[root@client ~]# systemctl enable postfix

 

 

To Restart postfix Mail server

 

 

[root@client ~]# systemctl restart postfix

 

 

Edit the /etc/postfix/main.cf file:

 

 

[root@client ~]# vi /etc/postfix/main.cf

myhostname = client.agoutam.com

mydomain = agoutam.com

myorigin = $mydomain

inet_interfaces = loopback-only

relayhost = 192.168.56.101

 

 

To Check the Postfix syntax of main.cf configuration file

 

[root@client ~]# postfix check

 

 

To Check the non-default configuration:

 

 

[root@client ~]# postconf -n

html_directory = no

inet_interfaces = all

inet_protocols = all

mail_owner = postfix

mailq_path = /usr/bin/mailq.postfix

manpage_directory = /usr/share/man

mydestination = $myhostname, localhost.$mydomain, localhost

mydomain = agoutam.com

myhostname = client.agoutam.com

myorigin = $mydomain

 

 

 

To Restart postfix Mail Server

 

[root@client ~]# systemctl restart postfix

[root@client ~]# systemctl enable postfix

 

 

To Send mail to user msgoutam ,user presents in Server Machine

 

[root@client ~]# echo "testmail" | mail -s "Testing relayhost " msgoutam@agoutam.com

 

 

To Check Maillog for mail msgoutam@agoutam.com

 

 

[root@client ~]# tail -10 /var/log/maillog

Oct 23 17:32:44 client postfix/smtp[2306]: 7B6C33098B13: to=<msgoutam@agoutam.com>, relay=192.168.56.101[192.168.56.101]:25, delay=0.17, delays=0.09/0.01/0.01/0.07, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as C86AC199FA1B)

 

 

 

To Check Mail for user msgoutam login as msgoutam

 

[root@server home]# su - msgoutam

Last login: Mon Oct 23 17:12:00 IST 2017 on pts/0

 

 

To check mail for user msgoutam ,using command mail:

 

 

[msgoutam@server ~]$ mail

Heirloom Mail version 12.5 7/5/10.  Type ? for help.

"/var/spool/mail/msgoutam": 3 messages 2 new

 A  1 root                  Mon Oct 23 17:11  20/614   "Test Mail to Agoutam"

>N  2 msgoutam@agoutam.com  Mon Oct 23 17:13  24/796   "Re: Test Mail to Agou"

 N  3 root                  Mon Oct 23 17:32  21/788   "Testing relayhost"

 

 

 

 

 

 

 

 

 

 

Type 3 to check Third mail from mail service .

 

& 3

Message  3:

From root@agoutam.com  Mon Oct 23 17:32:44 2017

Return-Path: <root@agoutam.com>

X-Original-To: msgoutam@agoutam.com

Delivered-To: msgoutam@agoutam.com

Date: Mon, 23 Oct 2017 17:32:44 +0530

To: msgoutam@agoutam.com

Subject: Testing relayhost

User-Agent: Heirloom mailx 12.5 7/5/10

Content-Type: text/plain; charset=us-ascii

From: root@agoutam.com (root)

Status: R

 

testmail

                   

 

 

Configure a system to forward all email to a central mail server

                Mail gateway configuration

 

Edit the /etc/postfix/main.cf file:

 

 

[root@client ~]# vi /etc/postfix/main.cf

myhostname = client.agoutam.com

mydomain = agoutam.com

myorigin = $mydomain

inet_interfaces = all

mydestination = $myhostname,localhost.$mydomain,localhost,$mydomain

mynetworks = 192.168.56.0/24,127.0.0.0/8

relayhost = 192.168.56.101

 

 

 

To Check the syntax of main configuration file main.cf

 

[root@client ~]# postfix check

 

 

 

To Check the non-default configuration:

 

 

[root@client ~]# postconf -n

alias_database = hash:/etc/aliases

alias_maps = hash:/etc/aliases

command_directory = /usr/sbin

config_directory = /etc/postfix

daemon_directory = /usr/libexec/postfix

data_directory = /var/lib/postfix

debug_peer_level = 2

debugger_command = PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin ddd $daemon_                                                           directory/$process_name $process_id & sleep 5

html_directory = no

inet_interfaces = all

inet_protocols = all

mail_owner = postfix

mailq_path = /usr/bin/mailq.postfix

manpage_directory = /usr/share/man

mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain

mydomain = agoutam.com

myhostname = client.agoutam.com

mynetworks = 192.168.56.0/24, 127.0.0.0/8

myorigin = $mydomain

newaliases_path = /usr/bin/newaliases.postfix

queue_directory = /var/spool/postfix

readme_directory = /usr/share/doc/postfix-2.10.1/README_FILES

relayhost = 192.168.56.101

sample_directory = /usr/share/doc/postfix-2.10.1/samples

sendmail_path = /usr/sbin/sendmail.postfix

setgid_group = postdrop

unknown_local_recipient_reject_code = 550

 

 

                           

 

 To send Mail to user agoutam@agoutam.com

 

[root@client ~]# echo "test Gateway Configuration" | mail -s "Testing Gateway Configurationrelayhost " agoutam@agoutam.com

 

 

To Verify Mail sent by viewing Mail log

 

 

[root@client ~]# tail -10 /var/log/maillog

Oct 23 18:10:25 client postfix/cleanup[3151]: 54BBE3098B13: message-id=<20171023124025.54BBE3098B13@client.agoutam.com>

Oct 23 18:10:25 client postfix/qmgr[3136]: 54BBE3098B13: from=<root@agoutam.com>, size=488, nrcpt=1 (queue active)

Oct 23 18:10:25 client postfix/local[3153]: 54BBE3098B13: to=<agoutam@agoutam.com>, relay=local, delay=0.09, delays=0.07/0.01/0/0.01, dsn=2.0.0, status=sent (delivered to mailbox)

Oct 23 18:10:25 client postfix/qmgr[3136]: 54BBE3098B13: removed

 

 

 

To check Mail login as agoutam

 

 

[root@client ~]# su - agoutam

Last login: Mon Oct 23 07:52:49 IST 2017 on pts/0

 

 

To Check mail type command mail logging as agoutam

 

 

[agoutam@client ~]$ mail

Heirloom Mail version 12.5 7/5/10.  Type ? for help.

"/var/spool/mail/agoutam": 2 messages 2 new

>N  1 root                  Mon Oct 23 17:47  18/625   "Testing Gateway Configuration relayhost"

 N  2 root                  Mon Oct 23 18:10  18/625   "Testing Gateway Configuration relayhost"

& q

Held 2 messages in /var/spool/mail/agoutam

[agoutam@client ~]$

 

 

To Install NMAP Tool for Verifying  Services.

 

 

 

[root@server ~]# yum install -y nmap

Loaded plugins: fastestmirror, langpacks

Loading mirror speeds from cached hostfile

Resolving Dependencies

--> Running transaction check

---> Package nmap.x86_64 2:6.40-7.el7 will be installed

--> Finished Dependency Resolution

 

Dependencies Resolved

 

================================================================== Package                              Arch                               Version                                         Repository              Size

=================================================================Installing:

 nmap                                 x86_64                            2:6.40-7.el7                                    base                    4.0 M

 

Transaction Summary

===================================================================

Install  1 Package

 

Total download size: 4.0 M

Installed size: 16 M

Downloading packages:

nmap-6.40-7.el7.x86_64.rpm                                              | 4.0 MB  00:00:00

Running transaction check

Running transaction test

Transaction test succeeded

Running transaction

  Installing : 2:nmap-6.40-7.el7.x86_64                                   Verifying  : 2:nmap-6.40-7.el7.x86_64                                

Installed:

  nmap.x86_64 2:6.40-7.el7

 

Complete!

[root@server ~]#

 

 

                                                                                                                                                                                                        

                                                                                            

 

 

 

 

To Verify SMTP Service and Port is running using NMAP tool

 

 

[root@server ~]# nmap server.agoutam.com

 

Starting Nmap 6.40 ( http://nmap.org ) at 2017-10-23 18:15 IST

Nmap scan report for server.agoutam.com (192.168.56.101)

Host is up (0.000023s latency).

Not shown: 987 closed ports

PORT     STATE SERVICE

21/tcp   open  ftp

22/tcp   open  ssh

25/tcp   open  smtp

53/tcp   open  domain

80/tcp   open  http

88/tcp   open  kerberos-sec

111/tcp  open  rpcbind

2049/tcp open  nfs

 

Nmap done: 1 IP address (1 host up) scanned in 0.18 seconds

[root@server ~]#

 

 

 

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