Boston Linux & UNIX was originally founded in 1994 as part of The Boston Computer Society. We meet on the third Wednesday of each month at the Massachusetts Institute of Technology, in Building E51.

BLU Discuss list archive


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Discuss] Strange sendmail (and postfix) spam issue: accepting fail "from" myself?



On Tue, Mar 29, 2016 at 02:09:15PM -0400, Derek Atkins wrote:
> So now I want to focus on Sendmail.  Any sendmail guru's out there?

Hello Derek!

Did you ever find a solution for this for Sendmail?  I would never
call myself a Sendmail guru, especially now--but I recall I spent some
time on trying to solve this a while back and failed.  It seems the
Sendmail folks believe that fixing this is a bad idea, because it can
block legitimate mail e.g. if someone at your site sends mail to
someone at another site that has a .forward file that points to an
address at your site.  In case that's not clear:

  From: foo at example.com
  To: bar at example.org

And bar at example.org has a .forward file that forwards to
baz at example.com.

Apparently, this message will get lost.  This seems like it should be
a fixable problem, but pffft.

I did just find this recipe, which appears to be outdated:

  http://www.sendmail.org/~ca/email/examples/Ted.html

I also thought SPF and/or DMARC would fix this, but I never got around
to trying to set any of that up...

-- 
Derek D. Martin    http://www.pizzashack.org/   GPG Key ID: 0xDFBEAD02
-=-=-=-=-
This message is posted from an invalid address.  Replying to it will result in
undeliverable mail due to spam prevention.  Sorry for the inconvenience.




BLU is a member of BostonUserGroups
BLU is a member of BostonUserGroups
We also thank MIT for the use of their facilities.

Valid HTML 4.01! Valid CSS!



Boston Linux & Unix / webmaster@blu.org