Software

Ask something
Discussion Locked

Email Loop

0 helpful
6 replies

by sven thirion

Closed to new repliesThis discussion is closed. It stays readable, but it takes no new replies.

This must have been discussed before, but I can't find it. Maybe someone can guide me in the right direction?

I have problems with our email server. Lately it is been going down from time to time because of email loops. I realized very early that this could happen; I just didn?t think it would happen that often.

Some of my users are using a white list which will send back an email to the sender if the sender is not recognized by the system. Due to our beloved spammers with their e-mail bounce attacks, one of their many emails was sent to a none existing user (in one case it was postmaster@... address) which then bounced the email to my user who used to be the fake ?from? address. As the bouncer was not recognized by my user it emailed the bouncer to verify it did send the email. The bouncer then bounced the email back to my user, and so on! I guess it will even work with an auto-response rule! This seems like it should be a common problem. How can I stop this?

Thanks!

6 replies

by sven thirion

Thanks for your reply. Basically, the solution is to turn the features off.

I was hoping more of solution that adds a tag to outgoing emails so that the server recognizes that this is a bounce of an email that was sent through our email server, so it wouldn't bounce it back.

by curlergirl

I've only found 2 possible solutions to this one - (a) turn of NDRs so that they don't bounce in the first place; or (b) implement spam control software that allows you to intercept these emails and delete them before they are delivered to your Exchange routing engine, or redirect them to a "catch-all" quarantine folder.

Hope this helps!

by zemi

I've never encountered the email loop problem but my company had a horrible spam problem. I've never thought much of 3rd party spam filtering companies but I decided to do a trial run of a company called mx logic. It works like a charm. The "out of the box" policies work perfect, the only change I made was to deny the delivery of emails that contain viruses. Everything else gets quarantined. Each user has a web portal they can log into and check their quarantined messages, after seven days they automatically get deleted. Haven't had one user complaint, user friendly. Users create their own white and black lists. Cost $50 a month for about 50 users. http://mxlogic.com

by ian lewis

You don't mention the name of the server you are using.

Configuration of Postfix, Exim or Exchange for example will differ. Some servers are better than others for this. Postfix for example will stop processing the mail when the headers exceed a certain size.

The first thing to do though is identify spam and quarantine it at the very least.

Also I'm not strictly sure that what you describe as an 'email loop' is a loop. Of course that is open for semantic analysis :)

by juan

Its time to make a change or upgrade. Some hosting
services take security to the extreme because they run
Exchange. Go to SGTmail.net We run Apple servers and
have been running flawless since we moved away from
Microsoft Exchange 4yrs ago. Our customers love all the
Outlook features online and all the free support. Our
customers come from other hosting services having
issues as you are. Now, we don't get any calls from our
current customers, just from new customers being refered
to us and lots of happy IT managers. Check us out, you
will love us too. Our base is 1GB and all the features.
Email delivered anyway you want it. Online package start
at $6.00 per account/month. no long term contracts,
POP3 start at $4.00 with 250MB server storage and online
access.
Good luck....

This discussion is closed to new replies.