Martijn Grendelman wrote:
> Hi,
>
> I am trying to make my fallback mail server reject mail for non-existent
> users during SMTP, so I want to do recipient verification callouts to
> the primary mail server.
>
> The problem is, that the fallback also relays mail for some domains that
> have different primary servers, and I don't want to do callouts to those
> servers.
>
> Is there a way to restrict verification callouts to certain hosts?
>
> The fallback does not have any authoritative knowledge about which
> domains end up at OUR primary, that is decided during routing exclusively.
>
> An ACL statement like:
>
> verify = recipient/callout=10s,defer_ok
>
> does the verification routing and the callout to the resulting target
> host at once, so I can't fix this in the ACL.
>
> I haven't found anything useful in the chapter about callout parameters
> in the manual. Any suggestions?
>
Just add a line in your ACL
domains = domain1.tld : domain2.tld
verify = recipient/callout=10s,defer_ok
