Re: tlug: External DNS woes

[Chris Sekiya <sekiya@example.com>]

On Thu, May 11, 2000 at 01:40:10PM +0900, Stephen J. Turnbull wrote:

> I'm having trouble with mail being intermittently refused from various
> sites because "Sender domain must exist."

... basic anti-spam measures added during the 8.9.x era check the SMTP envelope
from: address.  If it doesn't resolve, it fails the test.  If you're behind
a firewall, sending from a machine that doesn't have a lookup, it's going to
fail.

This is fixed by adding the following to your .mc:

MASQUERADE_AS( {your externally-visible MX} )dnl
FEATURE(masquerade_envelope)dnl

... so, no matter how badly your network admins botch things, mail should
still go through ...

-- Chris
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