nanog mailing list archives

Re: SOLVED? was Re: contact at yahoo mail?...


From: Leo Bicknell <bicknell () ufp org>
Date: Fri, 10 Oct 2003 12:42:33 -0400

In a message written on Fri, Oct 10, 2003 at 11:59:56AM -0400, Scott Stursa wrote:
They are blocking only the server where we put undergraduate accounts,
over 60% of which have forwarding set, most frequently to Hotmail, Yahoo
and AOL accounts. When the spam volume coming in here gets too high, our
server *appears* to be an open relay (which it is not).

This happens to my server a couple of times a week, but I've noticed
a slightly different pattern.

I also run a mail forwarding service.  What I notice is Yahoo seems
to delete a few accounts (not sure if this is an inactive deletion,
suspension, user closing, or what, all I know is it delivers right
before, and then gets "user unknown" right after).  About 10-30
minutes later, typically from a few spams to the user-unknown
addresses, the server gets blocked with "too many attempts to unknown
addresses".

Now, here's the problem, it now returns that for every yahoo e-mail.
So all the other people with forwards break, and more importantly
there is _NO_ way to tell what userid's are valid or not, short of
going back through the logs and finding the 10-30 minute window
where you got user unknown.  It can be a large amount of work. It also
of course backs up mail queues since they are returning temporary
errors for everything.

I have never had a similar problem with AOL or hotmail.

I submitted requests for help via their web form and they were just
ignored.

-- 
       Leo Bicknell - bicknell () ufp org - CCIE 3440
        PGP keys at http://www.ufp.org/~bicknell/
Read TMBG List - tmbg-list-request () tmbg org, www.tmbg.org

Attachment: _bin
Description:


Current thread: