Jonathan Vaughn:
> We receive mail directly from the internet, but not for this particular
> domain.
>
> This postfix also handles virtual mail for domains that aren't on Google
> apps, this is the only time it's listed as the MX. The only time it
> receives mail from outside our networks on this domain is if Google Apps is
> relaying it to us because it didn't have a match there.
The MX records for this domain point to Google only, and NOT to
your server? This is crucial. I would not support a solution that
lists both Google and your server as MX hosts. There is too much
risk of mail going into a loop.
> As for looping, can we somehow configure it so that while we relay via MX
> for unknown addresses from internal network, attempts to relay to unknown
> address from external fails (thus causing Google to see a bounce instead of
> looping) ?
Google MUST NOT accept mail for invalid recipients in this domain.
That would result in backscatter mail.
Again, this is crucial. I would not support a solution where Google,
as the primary MX host for this domain, can send invalid recipients
to your server.
Wietse
