Hello,
In our office we have a Postfix server which takes care of delivering email
inside and outside the office. For Internet mail it relays mail through the
ISP SMTP server. For this the relayhost parameter has been set to
relayhost=smtp.isp.tld.
We have a redundant Internet connection with the primary using ADSL and the
secondary using HSDPA. Both uses dynamic IP and due to this a lot of
legitimate mail is bounced as it is being sent from a dynamic IP host -
therefore the use of relayhost. The two Internet links are provided by two
different service providers and subsequently two different networks. The
ISP SMTP servers only relay for hosts connected to their respective
networks.
From time to time it happens that the ADSL link fails. An automatic switch
over happens to the HSDPA network but at that point no Internet mail is
delivered any more as the ADSL ISP bounces the mail indicating relay denied.
Is there a way of configuring Postfix to use two relayhosts. If the first
fails (cannot connect or bounce) then the second is tried automatically?
Thanks,
Albert
