Your setting Return-Path to YOU in your cygwin@cygwin postings

Mark J. Reed
Wed Mar 4 17:18:00 GMT 2009

On Wed, Mar 4, 2009 at 12:02 PM, Paul McFerrin wrote:
> I thank you both for enlightning me on this subject.
> I'm using the Thunderbird email client.  I have observed that it is wrongly
> using the "Return-Path" and not the "Reply-To" even in the email composing
> phase before the ISP gets involved.  I'll watch that more or seekout a RFC
> compliant email client.

Thunderbird is one of the more obsessively-RFC-compliant mail user
agents out there, and I would be quite surprised if this were the
case.  I see a bug reporting such behavior - - but that turned
out to be a side effect of the SMTP server, which was changing the
From: address to match the Reply-To.

This stuff is not hard to test:

$ sendmail -t <<EOF
To: <my email address>
Subject: Testing

Where does a reply go?

When the message arrived in Thunderbird, I hit "reply"; it correctly
addressed the reply to 'from.address', not 'return.path'.  So I don't
think your MUA is the problem.

Mark J. Reed <>

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