Unwanted messages in queue...

[basil116]

Hello...

Recently my users told me that email messages they had sent were not being delivered to the people they were sent to.

I checked the 'Outbound messages awaiting delivery' queue and found hundreds of unknown messages sitting in the queue. These messages were causing my user's messages to take along time to be delivered. When I delete the unwanted emails all my user's emails are delivered.

I have tested the server and it is not an 'open relay'.

This is what I see...

The emails look to be messages that could not be delivered and the server is attempting to re-send them.

The problem is that we did not send these messages. There is some spam thing going on here!

Is someone using one of our email address as a 'reply address'?

Any help would be appreciated.

Thanks...

 

[TravTrav]

I have the same problem...if anyone knows a fix, that would be great.

 

[crazypainter]

These seem to be all non-delivery reports automatically generated by exchange server when the delivery address does not exist. It could be from an ex employee who`s account has been deleted. This happened to me when a disgruntled employee was sacked, he joined everything he could on the net and I was bombarded with spam.
This is how I fixed it -
Create a distribution list and populate the list with the SMTP addresses of all past employees. The mail has somewhere to go so the system does not generate an NDR. And, since the messages don't go to a mailbox, they don't accumulate and take up room in the Exchange database.

 

[sheepie]

Hi All email (to genuine host domains) just sit in the outbound queue with the host unreachable message and wont go even after a retry YET if I highlight them all and then force it with a retry now they all go - this is most annoying as I have to keep checking the queue all the time - any ideas on this? thx

 

[sheepie]

Just a further note of bizzareness if I send an email from the web access page that goes in to the queue and goes straight away and if there are any sitting in there for the same host(ie hotmail.com) they also then go automatically - Weird.

 

[sheepie]

Hi have just sorted the problem - having deduced the mails get sent ok from OWA and not from the outlook client
When I sent a plain text from outlook this worked
I found that for some reason the HTML option under the MIME options on outbound mail was unticked and only plain text was alllowed - Put tick back in and HEY PRESTO all mails going straight out now - DOH

 

[sheepie]

No this hasn't worked - mail is still being queue up with host unreachable .

 

[basil116]

Regarding Crazypainter's response. That sounds correct for 'inbound messages' but the messages I am seeing are 'outbound'...

Basil

 

[basil116]

Also note in the image above the 'recipients' address. This is not us...

Basil

 

[devastator]

The problem you are having is this:

1. Your Exchange server is setup to recieve anything to @yourdomain.com.

2. If I send out a bunch of emails to people or accounts that don't exist on your Exchange email list, the Exchange server will accept them, find that there is no mailbox named 123@yourdomain.com thus trowing a <> NDR into the outbound que trying to notify the sender (SPAMMER) that there is no such person / email at this location.

3. Problem consists of the fact that the email addresses that your Exchange server is trying to respond to are forged / fake / non-existant so they sit in the que and wait for your default settings to give up delivery.

The only thing I have found that works is if you can put a proxy smtp in front of your Exchange box and set the accept to: from @yourdomain.com to your actual individual email addresses for your domain. I understand that if you have 30-100 users this isn't to bad, but once you get into 100's of users this method could be time consuming. Other than that I don't know of any other options to prevent this type of headache. That was a major problem for us even with everything relayed secured but since I implemeneted the above solution I can see the emails bouncing in the Firebox logs that are to non-existant emails on my domain. Takes the load off of the Exchange box and nothing sits in the outbound que.

P.S. We are using a WatchGuard Firebox III.

 

[Grenage]

Or you could disable NDR's to the Internet.

 

[devastator]

Where can you disable that in Exchange 5.5? I know there is a box to check in Exchange 2000 but I haven't found one in Exchange 5.5.


Dev

 

[Grenage]

Under the IMS, the Internet Mail tab, then the Notifications Button.