Posts Tagged ‘postfix mail system’

How to configure mail server forwarding on Postfix – Email forwarding from one Postfix SMTP to another

Friday, March 1st, 2013

I needed to configure mail forwarding from one Postfix mail server with a correct MX and PTR record to another one for a reason the second mail server has filtered port 25, because of ISP policy. As it is recommended in such situations, I've configured mail forwarding from postfix host1 to host2 to use (submission) port number 587 which general purpose is for exactly situations like this. Mail forwarding is done via a simple /etc/postfix/main.cf, /usr/local/etc/postfix/main.cf (depending where Postfix is installed).

Thus as my postfix configs are in /etc/postfix, I edited /etc/postfix/main.cf on forwarding Postfix mail server, where mail comes in (host1) and added line:

relayhost = [123.123.123.123]:587

Where 123.123.123.123 is IP address of host2

To load settings I had to do the usual postfix restart

postfix# /etc/rc.d/postfix restart

postfix/postfix-script: stopping the Postfix mail system
postfix/postfix-script: starting the Postfix mail system

On host2 – to which mail is forwarded, I had to add access for host1 to relay mail  in /etc/postfix/main.cf had to include:

mynetworks = 124.124.124.124

and 124.124.124.124 is IP of host1

One note to make is if mynetworks is not defined to host of host1 mail server, you will get in /var/log/maillog error:

Relay access denied (in reply to RCPT TO command))

Here is paste chunk from /var/log/maillog

Mar  1 08:57:01 host1 postfix/smtp[95236]: 88C8B11F911:
                    to=<amaderit.for.brother+caf_=amaderit2013FINAL=forward-host.org@gmail.com>, relay=24.129.36.212[24.129.36.212]:587, delay=0.54,
                    delays=0.01/0/0.44/0.09, dsn=5.7.1, status=bounced (host 24.129.36.212[24.129.36.212] said: 554 5.7.1
                    <amaderit.for.brother+caf_=amaderit2013FINAL=forward-host.org@gmail.com>: Relay access denied (in reply to RCPT TO command))

How to change default port 25 to 995 or any other on Postfix mail server

Wednesday, February 27th, 2013

If you need to change default mail delivery port of Postfix mail server from 25 to any other port lets say to 995. Here is how:

Edit /etc/postfix/master.cf  – a small note to make here is master.cf is located on same location on mostly all Linux distributions as well as FreeBSD.

Find line with:

smtp      inet  n       –       n       –       –       smtpd

Change smtp – which is actually a reference for port 25 to whatever port you need – i.e. 995 After change line should look like:

995      inet  n       –       n       –       –       smtpd

Save config file and restart postfix to load new settings:

# /etc/rc.d/postfix restart
postfix/postfix-script: stopping the Postfix mail system
postfix/postfix-script: starting the Postfix mail system