[svlug] Re: [svlug]Email to/from SVLUG
Derek J. Balling
dredd at megacity.org
Sun May 7 20:47:17 PDT 2000
At 9:50 AM -0700 5/7/00, Marc MERLIN wrote:
> > Seems there is nothing in "MAIL FROM:" which my exim rejects. That
>> prevents 99% of the spam.
>AFAIK, you send an Email with an empty envelope sender when that Email is a
>bounce and you don't want a bounce back.
>Also, the envelope sender doesn't look empty, it looks like it's
>svlug-admin at lists.svlug.org, which gets the Email bounces
You're correct. Rejecting mail sent with "MAIL FROM: <>" breaks
bounces, and is a Very Bad Thing(tm). If you send me mail, you should
be willing to (and the RFC's mandate you MUST) accept the bounces.
It is equally easy to forge "MAIL FROM: <>" as it is to forge "MAIL
FROM: <someone at some_other_domain.com>", so the null-reject is a
I've wondered aloud many times if a DNSBL (a la MAPS, ORBS, etc.) is
useful for listing what domains' MX's won't accept bounces back to
them, and allowing mail admins to prevent the bounce-double-bounce
loop from hitting their postmaster box when somebody misconfigures
their mail server....
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