Postfix + multiple relayhosts

Discussion in 'Installation/Configuration' started by warlock, Jun 1, 2010.

  1. warlock

    warlock New Member

    Hi Guys,

    How do I configure postfix to deliver to multiple smtp relay hosts.
    We have 2 internet connection on a WAN bonder, if 1 line goes down we'd like post fix to deliver to a secondary smtp relay host.

    I have tried this
    relayhost = and

    postfix: fatal: relayhost parameter setting must not contain multiple values:
    Is there an option to alternate for load balancing or at least for fail-over

  2. yui72o

    yui72o New Member

    You should check this tutorial :
    At 4.2 they configure /etc/postfix/
    and at 4.5 (most usefull for you) is the configuration of multiple relays
    Please note that I think it is not at all for any load-balancing but multiple relays for local mail (Don't think you can ever do that with postfix ...)

    I hope this will help
  3. XoCine

    XoCine New Member

    Maybe that question is ooooooooold but have some nice solution :)

    Well warlock, in searching of solution I did some googling but did not found solution sooo I turned off Google and enable a Brain++ :->

    What we want? That Postfix connect to one of FEW hosts (relayhosts).

    Welll, lets play with DNS :)

    In example do domain lets make some A lines:

    mxr IN A
    mxr IN A
    mxr IN A
    mxr IN A
    mxr IN A

    Lets flush bind and what we have? Nice :)

    [root@anubis postfix]# host has address has address has address has address has address

    Standard roundrobin rulez :-D

    Then only that little line in postfix/

    relayhost =

    and Postfix relays with every of these ips in roundrobin style :)

    Maybe it does not work as failover but better have 3/5 relays working then none :) 60% delivered mails at once, rest waits for some time

    Simple and nice :) Hace fun :)
    Last edited: Jul 20, 2011

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