Postfix and OMV firewall

  • Hello all,
    I have a problem and cannot find the bug. I am running with postfix (for notifications) and the OMV firewall. The mail connection to GMail works fine but only if I open the OMV firewall completely (all IPs and all ports). If I only open ports 587 and 25, the connection times out and nothing gets delivered.
    Any ideas what the problem could be?


    Many thanks!

    OMV4 on ProLiant N54L + 5 x 3.5'' WD/Seagate HDs

    OMV5 on Raspberry Pi4

  • Specifying a source port in a firewall rule is almost always a mistake. The number of cases where this is required are miniscule. So stop doing that.


    The rules specifying destination ports 587 and 25 are not needed. Delete these.


    I don't know what you are trying to accomplish with the rest of your rules.


    If your OMV machine does NOT have a public IP address (it's behind a router on a private LAN IP address) you don't need the OMV firewall at all unless you have a very specific use case that requires it. Most users do not need it.

    --
    Google is your friend and Bob's your uncle!


    OMV AMD64 5.x on Chenbro NR12000 1U 1x 8m Quad Core E3-1220 3.1GHz 16GB ECC RAM.

  • Hi - thanks for your feedback. I will amend. The server is behind a router with a public IP address and I am forwarding several ports from the router to that OMV server. Therefore I want the OMV firewall in place to be tight. And it all works fine apart from the postfix, which times out unless I open the OMV firewall up entirely (currently top line).
    Do you see what the issue is here?

    OMV4 on ProLiant N54L + 5 x 3.5'' WD/Seagate HDs

    OMV5 on Raspberry Pi4

  • I suggest not using the firewall unless you have very specific well defined reasons for doing so. Then, every single rule you create has to meet a specific need, and has to be properly defined and sequenced.

    --
    Google is your friend and Bob's your uncle!


    OMV AMD64 5.x on Chenbro NR12000 1U 1x 8m Quad Core E3-1220 3.1GHz 16GB ECC RAM.

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