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?
Thanks,
Martijn.