Getting 6000 undelverable messages a day!! (HELP)

[fend78]

I recently started receiving constant undeliverable e-mails from two domains, i receive 1 about every ten seconds constantly.

I checked my exchanged 5.5 and it is not set for relay.

Whenever I get to the office i have about 6000 undeliverable messages.

I tried filtering out the domain and ip address in exchange, which stops it for a day or so but then it keeps coming back.

I setup the rules wizard in outlook xp to delete any incomming messages. Which once again stooped it for a day or so. But they are still back.

Does anyone have an idea on how to stop this?

Thanks

 

[eightball]

Do you think someone is spamming you? Are you the list Exchange admin in the administrator? Well looks like you already covered the basics. So what is the name domain these are coming from? Is it just hitting one mailbox? Ping the domain and see where it is coming from. Do this a few times to see if the domain adress is changing. a spammer may be spoofing the address. If it is hitting just one mailbox, disable it. I would get some kind of firewall up. you can also setup reverse dns. If the domainname is changing then let me know. Try this again though. To prevent all users in a specific domain from delivering messages to your site, type the domain name in the following format:
@domainname.com

If you want the Internet Mail Service to automatically delete junk e-mail messages, click to select the Delete messages instead of moving to turf directory check box

 

[Marcs41]

How can they come back if you blocked the domain?
What is in the messages? Is it a virus or spam? [sub]If the answer is here, Mark it, others can benefit from it too. If 'something' 'somewhere' gives 'some' error, excpect random guesses or no replies at all. Please specify details.
Free Tip: The F1 Key does NOT destroy your PC!
Marc[/sub]

 

[eightball]

I assume the email is coming back by changing the domain. Or the setup is corrupt. Try rebooting the server. You could stop & restart the IMC mail service, but a reboot should give you a fresh start since you have all the other exchange services. I think this might be this simple to resolve.

 

[Grenage]

I would most certainly do a virus scan on your network machines. While that is running in the background, can you see the properties of one of these emails at all ?

The names can be spoofed but if the emails are coming from your domain the IP should be listed?

 

[johnny99]

You didn't tell us what user is getting the emails.
Is it the same, you or postmaster?

If you get a copy of all mails with error (so they are not yours) check the two domain names and the ip-numbers.

I have seen problems that could look a little like this. One user set all his mail to be forwarded to his hotmail account. That got filled up and every time we forwarded an email to him we got an error back that we again forwarded and we got a great loop.
I don't remember if it was Hotmail or another service, and I also think that both Hotmail and Yahoo have closed this "loop hole". But it could happen on other sites.

You could also get this problem if a user if forwarding his emails to a wrong email address.

 

[muuasammy]

Hi I have an error of bouncing mail to another domain.
Its only for a specific user; i can ping their server and i'm sure its not virus related. I stopped IMC and restarted it again but nothing happened;we normally route our outbound mail to via smtp.
Any help?

 

[johnny99]

So it's the same user sending emails to a single (or two) email addresses outside your site that bounces?

 

[makai]

Post the NDR