Re: [exim] Re-routing mail to the secondary MX server

Am 12.01.22 um 16:02 schrieb Dmitriy Matrosov via Exim-users:
> Hi.
>
> Is it possible to re-route certain mails on the primary server (with
> lowest MX priority)
> to the secondary (the one with highest priority)?
>
> My use case is if the recipient is not found on the primary server,
> try to deliver a message to the secondary server (which is controlled
> by another person).
>
> Thanks.
>

SMTP Server are backupservers, with the same address setup.

Your primary should take the mail and send it to the second server, or,
easier: use a subdomain for the secondserver and his addresses, as any
subdomain can have it's own MX entry. Example:

domain.com. IN MX  0 mx.domain.com
berlin.domain.com. IN MX  0 mx.berlin.domain.com


If you want one  @domain.com with two distinct servers, take it on any
of them and reroute it :

for your secondary

secondmx:
  driver = manualroute
  domains = +local_domains
  condition = ... your condition for a message to your primary server...
  transport = remote_smtp
  route_data = mx.primary.domain.com
  ignore_target_hosts = 0.0.0.0 : 127.0.0.0/8
  no_more

for your primary

secondmx:
  driver = manualroute
  domains = +local_domains
  condition = ... your condition for a message to your secondary server...
  transport = remote_smtp
  route_data = mx.secondary.domain.com
  ignore_target_hosts = 0.0.0.0 : 127.0.0.0/8
  no_more


Each one should stand BEFORE the "dnslookup"-router in it's version of
your exim.conf, depending on the server it is on.

Best regards,
Marius