RHCE Series: SMTP



[[email protected] postfix]# vim /etc/postfix/main.cf
[[email protected] postfix]# service postfix restart
Shutting down postfix: [ OK ]
Starting postfix: [ OK ]
[[email protected] postfix]# egrep 'myhostname|mydomain|inet_interfaces|mydestination' /etc/postfix/main.cf
myhostname = server1.example.com
mydomain = example.com
inet_interfaces = localhost, $myhostname
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain

Now that postfix is setup, let's send mail.
[[email protected] ~]# mail [email protected]
Subject: test
Hello. This is a test.
.
EOT

Now to check the logs on the mail server and check the message.





Oct 28 00:33:19 server1 postfix/smtpd[4556]: connect from client1.example.com[192.168.1.11]
Oct 28 00:33:19 server1 postfix/smtpd[4556]: A312D4D42: client=client1.example.com[192.168.1.11]
Oct 28 00:33:19 server1 postfix/cleanup[4559]: A312D4D42: message-id=<20121028053319 .81b8f3fccc=".81b8f3fccc" client1.example.com="client1.example.com">
Oct 28 00:33:19 server1 postfix/qmgr[4554]: A312D4D42: from=, size=649, nrcpt=1 (queue active)
Oct 28 00:33:19 server1 postfix/smtpd[4556]: disconnect from client1.example.com[192.168.1.11]
Oct 28 00:33:20 server1 postfix/local[4560]: A312D4D42: to=, relay=local, delay=0.59, delays=0.24/0.22/0/0.14, dsn=2.0.0, status=sent (delivered to mailbox)
Oct 28 00:33:20 server1 postfix/qmgr[4554]: A312D4D42: removed

[[email protected] postfix]# mail
Heirloom Mail version 12.4 7/29/08. Type ? for help.
"/var/spool/mail/root": 1 message 1 new
>N 1 root Sun Oct 28 00:33 21/793 "test"
& 1
Message 1:
From [email protected] Sun Oct 28 00:33:20 2012
Return-Path:
X-Original-To: [email protected]
Delivered-To: [email protected]
Date: Sun, 28 Oct 2012 00:33:19 -0500
To: [email protected]
Subject: test
User-Agent: Heirloom mailx 12.4 7/29/08
Content-Type: text/plain; charset=us-ascii
From: [email protected] (root)
Status: R

Hello. This is a test.


Now, let's set up a mail relay to forward mail to client1.example.com

We need to add an entry called 'relayhost' to /etc/postfix/main.cf on server1.example.com. Then restart postfix.
relayhost = client1.example.com

[[email protected] ~]# mail [email protected]
Subject: test
this is a test.
.
EOT
[[email protected] ~]# tail -f /var/log/maillog
Oct 28 00:45:37 server1 postfix/postfix-script[4797]: starting the Postfix mail system
Oct 28 00:45:37 server1 postfix/master[4798]: daemon started -- version 2.6.6, configuration /etc/postfix
Oct 28 00:45:37 server1 postfix/qmgr[4801]: 590394D43: from=<>, size=2479, nrcpt=1 (queue active)
Oct 28 00:45:42 server1 postfix/smtp[4803]: 590394D43: to=, relay=client1.example.com[192.168.1.11]:25, delay=856, delays=851/0.03/5/0.08, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as 5B1293FCCD)
Oct 28 00:45:42 server1 postfix/qmgr[4801]: 590394D43: removed
Oct 28 00:45:57 server1 postfix/pickup[4800]: 00CB44D43: uid=0 from=
Oct 28 00:45:57 server1 postfix/cleanup[4809]: 00CB44D43: message-id=<20121028054557 .00cb44d43=".00cb44d43" server1.example.com="server1.example.com">
Oct 28 00:45:57 server1 postfix/qmgr[4801]: 00CB44D43: from=, size=444, nrcpt=1 (queue active)
Oct 28 00:45:57 server1 postfix/smtp[4803]: 00CB44D43: to=, relay=client1.example.com[192.168.1.11]:25, delay=0.26, delays=0.21/0/0/0.04, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as 1B9B43FCCD)
Oct 28 00:45:57 server1 postfix/qmgr[4801]: 00CB44D43: removed

Oct 28 00:45:57 localhost postfix/smtpd[2980]: connect from unknown[192.168.1.1]
Oct 28 00:45:57 localhost postfix/smtpd[2980]: 1B9B43FCCD: client=unknown[192.168.1.1]
Oct 28 00:45:57 localhost postfix/cleanup[2984]: 1B9B43FCCD: message-id=<20121028054557 .00cb44d43=".00cb44d43" server1.example.com="server1.example.com">
Oct 28 00:45:57 localhost postfix/qmgr[2978]: 1B9B43FCCD: from=, size=628, nrcpt=1 (queue active)
Oct 28 00:45:57 localhost postfix/smtpd[2980]: disconnect from unknown[192.168.1.1]
Oct 28 00:45:57 localhost postfix/local[2985]: 1B9B43FCCD: to=, relay=local, delay=0.07, delays=0.04/0/0/0.03, dsn=2.0.0, status=sent (delivered to mailbox)
Oct 28 00:45:57 localhost postfix/qmgr[2978]: 1B9B43FCCD: removed

[[email protected] postfix]# mail
Heirloom Mail version 12.4 7/29/08. Type ? for help.
"/var/spool/mail/root": 2 messages 2 new
>N 1 Mail Delivery System Sun Oct 28 00:45 78/2739 "Undelivered Mail Returned to Sender"
N 2 root Sun Oct 28 00:45 21/772 "test"
& 2
Message 2:
From [email protected] Sun Oct 28 00:45:57 2012
Return-Path:
X-Original-To: [email protected]
Delivered-To: [email protected]
Date: Sun, 28 Oct 2012 00:45:56 -0500
To: [email protected]
Subject: test
User-Agent: Heirloom mailx 12.4 7/29/08
Content-Type: text/plain; charset=us-ascii
From: [email protected] (root)
Status: R

this is a test.

Be sure to chkconfig postfix to ensure it will be persistent at boot and you'll need to make sure that iptables will allow the smtp traffic as well.