Plesk updates network protocols in Postfix configuration


2016-11-16 13:06:45 UTC


2017-08-16 16:56:14 UTC


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Plesk updates network protocols in Postfix configuration

Applicable to:

  • Plesk 12.5 for Linux
  • Plesk Onyx for Linux
  • Plesk 12.0 for Linux


Plesk updates /etc/postfix/ setting inet_protocols = all , for example, after running plesk repair mail command.


This is Plesk bug with ID #PPP-9435 that is planned to be fixed in future Plesk updates.


As a workaround, enforce Postfix to use IPv4 by specifying inet_protocols parameter in configuration file:

  1. Open /etc/postfix/ with text editor (for example, vi) on the Postfix service node.

  2. Change inet_protocols value from inet_protocols = all to inet_protocols = ipv4 .

  3. Restart Postfix service:

    # /etc/init.d/postfix restart

It defines what protocols Postfix will use, when it makes or accepts network connections, and also controls what DNS lookups Postfix will use, when it makes network connections.

For additional information, please, check Postfix documentation .

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  • 0
    Greg Sims

    Any time Plesk updates /etc/postfix/, it will set inet_protocols = all.  If you choose to change this setting to inet_protocols = ipv4 , you also need to monitor any change Plesk makes to /etc/postfix/  When Plesk makes a change to, it will change the setting back to inet_protocols = all.  It is your responsibility to know Plesk changed /etc/postfix/ so you can reapply setting inet_protocols = ipv4 after each Plesk update.

    Edited by Greg Sims
  • 0
    Artyom Baranov

    Hello Greg,

    I have attempted to reproduce the reported behavior on Plesk Onyx (CentOS 6), however, 'inet_protocols' parameter stays unchanged after changing mail server settings via Plesk.

    Could you please shed some light on the issue and let us know:

    1. Plesk version and OS you are using.

    2. Actions with Postfix that result in 'inet_protocols' parameter changing.

    Thank s in advance!

  • 0
    Greg Sims

    We are using Plesk 12.5 on CentOS 7.  We monitor changes in to ensure when Plesk overrides we can adjust according.  Please run 

    plesk repair mail -y -v

    and watch changes in /etc/postfix/  Please also see internal support ticket 21903 for other data that is changed Postfix configuration by Plesk when this command is run. Would it be possible to document what is changed and what is not based on input from developers?


  • 0
    Artyom Baranov

    Hi Greg,

    Thank you for the valuable update!

    I have passed the information about such behavior to our developers.

  • 0
    Alexander Tsmokalyuk

    @Greg The bug was confirmed, the article has been updated. Thanks! 

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