Does Microsoft Exchange retry delivery correctly?

Vernon Schryver
Sat Sep 16 15:42:55 UTC 2006

> > One such server identified itself as `Microsoft ESMTP MAIL Service,
> > Version: 6.0.3790.1830' in its SMTP banner, and as `Microsoft Exchange
> > V6.5' in the e-mail headers.  Is this a recent version?  I'm wondering
> > if a recent change broke the retries.  Does anyone know of a patch or
> > a configuration option that corrects this behavior?
> microsoft exchange DTRT.  these are probably forged identity headers coming
> from a botted host running spamware.

That is a very good thought, provided the body of the message looks like spam.
Since the greylisting code in the DCC clients delays the 4yz temporary
until the end of the DATA command, the body of the message is available
in the /var/dcc/log directory.  This is differs from other greylist and
other spam filter schemes, and is why the "Microsoft Exchange V6.5" string
was available, perhaps from a Received header.

One should be careful about assuming that Microsoft ever does the right
thing, even if it once did.  I recently found that current versions
of Internet Explorer complete trash the BUTTON element in two
different ways making it not only no better than INPUT, but unusable.
It's not as HTML 4 from 1999 is new.

but I guess that's an unrelated rant.

Vernon Schryver

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