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Curtis Maurand put forth on 6/1/2010 2:13 PM:
> I was editing the table by hand, but it seemed to be easier to do via
> the dbmail administrator and the mysql lookup. two domains, I'm simply
> filtering mail for and then sending along to their exchange server via
> smtp (sort of a postini type service.).
You need to be using recipient address verification. It was designed
specifically for this scenario. It is realtime and fully automatic, using
SMTP queries to downstream servers to determine valid users. Set it up once
and you're done. No databases to maintain.
As an example, Nortel Networks uses this technique (although with qpsmtpd, not
Postfix, IIRC) to route mail through a few smtp gateways to hundreds of
internal domains and over 50k+ users worldwide. They have divisions using MS
Active Directory and Exchange, some using Novell eDirectory and Groupwise,
some using Lotus Notes, others using ??. The sheer magnitude of attempting to
tie all of these disparate systems together just to identify valid recipients
would have cost multiple millions and would have never worked correctly due to
directory synchronization issues.
SMTP based recipient address verification was(is) the simple, elegant
solution, as all of these disparate mail platforms have SMTP in common, and
SMTP has a mechanism for recipient address verification. In essence this
solution is "free" of cost and complexity, and works extremely well.
It's really the only way to fly: