How to change default OS MTA to the ZCS Postfix

System email on a Zimbra server normally uses the system’s own MTA. To send system mail using the Zimbra mailer instead of the default OS MTA, follow these steps. Backup default OS MTA

[root@EzyMail ~]# mv /usr/sbin/sendmail /usr/sbin/sendmail.orig

Backup mailq

[root@EzyMail ~]# mv /usr/bin/mailq /usr/bin/mailq.orig

Create a link so that the system uses sendmail from the Zimbra MTA.

[root@EzyMail ~]# ln -s /opt/zimbra/postfix/sbin/sendmail /usr/sbin

Create a link so that the system uses mailq from the Zimbra MTA.

[root@EzyMail ~]# ln -s /usr/sbin/sendmail /usr/bin/mailq