LinuxHostingSupport

Plesk supports Qmail and Postfix mail servers, however, only one MTA (Message Transfer Agents) can be installed and used at a time. To check the current MTA in use, look at

Plesk -> Settings -> Services Management

OR you can execute the following command from SSH

# /usr/local/psa/admin/bin/mailmng --features | grep SMTP_Server 

$features['SMTP_Server'] = "QMail"; 

$features['SMTP_Server_package'] = "psa-qmail";

The above output shows that Qmail is currently your Mail server. Plesk offers an ‘autoinstaller’ script to install/upgrade various components, and is used to switch from Qmail to Postfix OR vice-versa.

Stop the SMTP service before you switch between the Mail servers, to avoid accepting of new emails and to deliver the emails that are in the mail queue.

Stop the SMTP service:

# /usr/local/psa/admin/sbin/mailmng --stop-smtpd

Switch MTA from Qmail to Postfix:

# /usr/local/psa/admin/sbin/autoinstaller --select-release-current \ 

--install-component postfix

OR switch MTA from PostFix to Qmail:

# /usr/local/psa/admin/sbin/autoinstaller --select-release-current \ 

--install-component qmail

That’s it.

Note: The change of mail server won’t change the mail format and the directory location where the messages are stored. However, the emails in the mail queue will be removed since the MTA is reconfigured.