prevent overlapping postfix services

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prevent overlapping postfix services

Postby rotorboy » Sat Jan 13, 2018 6:01 pm


We had that very annoying situation where what should have been a simple server shutdown, switch power source, server start-up resulted in an hour of frustration. Somewhere between the last time we rebooted this Zimbra server and today CentOS decided to re-add postfix to it's start-up list so that when Zimbra tries to start postfix properly it finds the port is already bound and in use.

Jan 13 08:20:24 zimbra postfix/master[15322]: fatal: bind port 25: Address already in use

So we have to check to see what's listening on port 25

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[root@zimbra ~]# netstat -lnp |grep :25

tcp 0 0* LISTEN 1932/master
tcp6 0 0 ::1:25 :::* LISTEN 1932/master
[root@zimbra ~]# ps -ef | grep 1932
root 1932 1 0 08:09 ? 00:00:00 /usr/libexec/postfix/master -w
postfix 1977 1932 0 08:09 ? 00:00:00 pickup -l -t unix -u
postfix 1978 1932 0 08:09 ? 00:00:00 qmgr -l -t unix -u
root 30599 4741 0 08:35 pts/0 00:00:00 grep --color=auto 1932

And then we shut down postfix

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systemctl stop postfix.service

Next we restart the mta (and make sure everything else is running)

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/etc/init.d/zimbra start

Starting zmconfigd...Done.
Starting dnscache...Done.
Starting logger...Done.
Starting convertd...Done.
Starting mailbox...Done.
Starting memcached...Done.
Starting proxy...Done.
Starting amavis...Done.
Starting antispam...Done.
Starting antivirus...Done.
Starting opendkim...Done.
Starting snmp...Done.
Starting spell...Done.
Starting mta...Done.
Starting stats...Done.
Starting service webapp...Done.
Starting zimbra webapp...Done.
Starting zimbraAdmin webapp...Done.
Starting zimlet webapp...Done.

Next is to disable it from starting up automatically

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systemctl disable postfix

Removed symlink /etc/systemd/system/

How do we make CentOS 7 never re-enable postfix?

Perhaps a solution might be for the Zimbra start-up script (in /etc/init.d/zimbra) to be modified to first try and shut down any existing postfix services before it starts it's own services?

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Re: prevent overlapping postfix services

Postby DualBoot » Sun Jan 14, 2018 2:48 pm


best solution is to have a minimal CentOS installation and purge the Postfix package.
I have already encounter this kind of problem with chkconfig, each time there was
an update of postfix, it re-enabled the postfix service.
Another solution it is to point the Postfix Unit in Systemd to the Zimbra Postfix binary ?


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