[RndTbl] mail server help

Trevor Cordes trevor at tecnopolis.ca
Fri Aug 18 02:00:18 CDT 2017


On 2017-08-17 Micah Garlich-Miller wrote:
> I forgot to mention: the timestamps on your problem emails happen
> before they started work on the ironports. So I don't think it's
> related.
>
> >  >>> DATA  
> > <<< 550 <trevor at tecnopolis.ca>... 451 4.7.1 Greylisting in action,
> > please come back later

Thanks guys, Gilbert was right, the problem was on my side.  I upgraded
to Fedora 26 2 weeks ago, and that's the only time sendmail and
milter-greylist changed, but I thought, nah, this couldn't have been
broken for a whole 2 weeks and I'm just hearing the complaints now!
Dropping email for 2 weeks... don't even want to think about that...

But, a quick telnet port 25 and some commands later, yup, it's me.
Looks like a bug that hit in 2015 and was supposedly fixed but is now
regressed.  It could be a Fedora thing, as it looks like it's a missed
patch because Fedora is still using sendmail 8.15 instead of 8.16
(why?) which has the official fix.

https://bugzilla.redhat.com/show_bug.cgi?id=1482808

The quick fix:
dnf downgrade sendmail

Now gives me correct:
451 4.7.1 Greylisting in action, please come back later
instead of buggy:
550 <validuser at problemsendmailhost.com>... 451 4.7.1 Greylisting in
action, please

And yes, it looks like I'm once again the first one in the world using
Fedora 26 + sendmail + greylist.  Bah.  Always the guinea pig.  Oh
well, it is my pleasure to serve, so all you CentOS/RHEL people can have
your bug-free major releases ;-)

>From my bz, as to why this wasn't immediately noticeable:
It's really insidious because email doesn't just stop: there are still
2 cases where emails get through: the tuple is in gm's hard or
auto-whitelist, or the end user resends the email after the gm timeout
period.  So many emails will get through and mail admins may not know
there is a problem until they start getting some phone calls about the
sporadic missing emails...

Thanks to Adam for testing too.



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