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Date: Thu, 24 Jul 1997 14:40:22 -0500 (CDT)
Reply-To: Anthony.Kimball@East.Sun.COM
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From: Tony Kimball <Anthony.Kimball@East.Sun.COM>
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To: nate@mt.sri.com
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Subject: Re: (over)zealous mail bouncing 
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Quoth Nate Williams on Thu, 24 July:

: That's irrelevant.  Most machines which send mail send via a machine
: that *DOES* have valid hostnames, and the envelope uses that address.
: That's the way email has always worked.

Quite so.  I had not correctly understood that the 'valid hostname'
criterion was being limited to the MAIL FROM: field.  I suppose (not
having messed with sendmail.cf extensively for quite some time and not
being familiar with the practices of those who do this filtering) that
the checking can be easily deferred until after suitable extraction of
the address have been performed, so that the DNS resolvable part is
used.