Educause Security Discussion mailing list archives
Re: Mysterious Email Problems
From: Theresa M Rowe <rowe () OAKLAND EDU>
Date: Fri, 12 Sep 2003 20:51:04 -0400
Wow, I thought we were alone. We have some cases where the mail doesn't deliver from some locations, and in some cases it comes days late. We've tried working this out with our vendor and the organizations involved. Technically we believe the problem is as follows: The MX record of the destination domain is not present in the default DNS query, therefore, our mail server does not see a legitimate destination mail system and causes the failure reported. In some cases the primary entry isn't processed because it is not "valid" but several days later a secondary entry will work. We've been exploring the following items: (1) When we moved from BIND to Windows DNS in December of 2002, did the "query mechanism" change? (2) Are the differences between the registration records for the sites that work and the sites that don't work significant to the problem we are experiencing - but that doesn't pan out. We note here that several of the places with email disruption are medical facilities - hospitals in particular. Are they doing something different? Theresa Rowe ---- Original message ----
Date: Fri, 12 Sep 2003 16:29:32 -0700 From: gmalone <gmalone () PCC EDU> Subject: [SECURITY] Mysterious Email Problems To: SECURITY () LISTSERV EDUCAUSE EDU Hello Group, Over the last two or three months, Portland Community
College (PCC) has had
mysterious email problems related to receiving incoming
email messages. A
college or vendor will send an email message to an
individual at PCC and
sometimes it will go through and sometimes it won't. We
have worked with
two vendors and two universities to try and determine the
root cause of the
problems. It appears that when the sending email server
sends a reverse
look-up for our domain it can find it sometimes and other
times it
can't. We have checked and rechecked our external DNS
records. We have
even had IT staff at the sending institution perform DNS
look-ups at the
same time a message is sent. We have found cases where the
DNS look-up
will work but the email will be rejected because our domain
is
unknown. I've been told that both of the universities we
are working with
have similar intermittent problems. We have heard and discussed several theories such as the
Spam software may
be casing the problem, or the need for a second
authoritative DNS server
out side PCC, and even the possibility that the virus
problem may be
causing this by flooding segments of the Internet
periodically. I'll admit
that this is not my area of expertise and all these worms
and viruses have
caused us all to second guess our fundamental strategies. I
like to find
out if this is an issue unique to PCC so I can decide what
actions to take
next. Are there other colleges or universities out there
who have been
experiencing problems like this? If so were you able to
determine the
root cause? Thanks. Greg =============================================================
==============
Greg Malone Portland Community College Manager, Technical Services Sylvania Campus CC219 12000 SW 49th Ave Portland, OR 97280-0990 email: gmalone () pcc edu Phone: (503) 977-4390 Fax: (503) 977-4390 =============================================================
==============
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Current thread:
- Mysterious Email Problems gmalone (Sep 12)
- <Possible follow-ups>
- Re: Mysterious Email Problems Theresa M Rowe (Sep 12)
- Re: Mysterious Email Problems Prof Vaughn (Sep 12)
- Re: Mysterious Email Problems GREGORY SCHAFFER (Sep 13)
- Re: Mysterious Email Problems Barros, Jacob (Sep 15)
- Re: Mysterious Email Problems Brian Kaye (Sep 15)