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SOME external email senders receiving "Receipient address rejected: User unknown in virtual alias table"

BruceCrum
BruceCrum asked
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Last Modified: 2013-11-30
Our company is using Microsoft Exchange 2003 SP2 as our email server.

We are receiving 100s of emails from other domain users each day.

We have a couple of other domain email people who are trying to send us email, but say that they are receiving the message: "Recipient address rejected: User unknown in virtual alias table"

We can send email to them, but when they reply, they receive the message above.

I am unable to find anything in the event log or via Message tracking center for the user@outsidedomain who are receiving the message above.

How can I track this and resolve it?

Thanks in advance.

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David BeveridgeLinux Systems Admin
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Commented:
This really doesn't make a lot of sense.  It shouldn't happen.  Can you have them forward you the full email error message and post it here.

Are you also sure that the same email address works from some places and not others?

There must be more to this story.  Can you find more specifics about the servers in question.

Author

Commented:
I will  try to get them to forward the full email to one of my outside email accounts.

Yes, I am sure that user1@ourdomain is receiving email from  bob@otherdomain, sam@otherdomain2, etc.,  but not from dave@problemdomain.

I did find that problemdomain.com's email is hosted at hostcompany.com.   When I do a nslookup for problemdomain.com, there is a A record for mail.problemdomain.com and a MX record that points to mx1.hostcompany.com.

I will try to get the additional error message information.

Thanks.

Author

Commented:
Just a further clarification:

No one at ourdomain.com is receiving email from dave@problemdomain.com.   Dave gets same rejection message no matter who he sends to at ourdomain.com
Try detaching and reattaching the mailbox.

To do this go to your exchange server and then to active directory user and computers. From that Select the user having  the problem receiving mail, and run exchange tasks and remove Exchange attribute.

To reattach go to Exchage System Manager and go to the store where this mailbox exists and right click mailbox cleanup agent by right clicking on the mailbox folder. Then Select the mailbox from the list and right click and choose reconnect and provide the username.

With Regards,
M Shajid Ali

Author

Commented:
ShajidAli,

Perhaps you did not have to opportunity to see my latest post that indicated, no one in our domain can recieve email from problemdomain.com.

Your solution would require that I detach and reattach every mailbox in our domain.  Are you still of that opinion with the additional information?

Thanks for the consideration though...
David BeveridgeLinux Systems Admin
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Commented:
See here's the thing...
This error. "User unknown in virtual alias table" is typically generated by a postfix or sendmail server that thinks that it is the server that hosts that domain.   If the customer at problem domain uses an ISP that you once used, and the ISP hasn't cleaned up his records or hasn't been told you've got your own server now, then this could happen.

What sort of server does the user at problemdomain have?
Does his server send his mail directly to your server?
Which server generates the bounce message?

David BeveridgeLinux Systems Admin
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Commented:
Did you ever use hostcompany.com?
David BeveridgeLinux Systems Admin
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Commented:
Is your website hosted at hostcompany.com?

Author

Commented:
BevHost,

I'm working on getting the bounce message details from dave@problemdomain.com.

I don't know their email setup, but from digging via domain registrations, I'm inclined to think that the email is coming from the hosting company, or at least routed through them.  Plus I found the hostdomain.com mx1.hostdomain.com IP address in my firewall logs.

ourdomain.com has never used hostdomain.com for either website or email.

David BeveridgeLinux Systems Admin
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Commented:
does everyone that gets the problem belong to the same domain or hosting company?

Author

Commented:
bevhost,

So far, everyone from problemdomain.com sending email to ourdomain.com is receiving the same rejection message.

I know the mail is getting through our firewall to the Exchange server, and I have found entries in the Exchange.log file for dave@problemdomain.com.  But the message is not delivered, it does not show up in the Message Tracking Center, and dave receives the rejection message.
David BeveridgeLinux Systems Admin
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Commented:
Does problem.com have an SPF Record
See
www.openspf.com
This one is on us!
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Author

Commented:
bevhost,

I've reviewed the SPF settings, but can't determine how to tell whether hostingcompany.com has a SPF record.
This one is on us!
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David BeveridgeLinux Systems Admin
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Commented:
Goto http://www.mxtoolbox.com/spf.aspx to lookup an SPF record or one of the other tools like it.

If you are not using Sender ID blocking then it doesn't matter anyway.

Looking at the logs is a good plan.

David BeveridgeLinux Systems Admin
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Commented:
You seem to have contradicted your self.
You say that you see from the logs that it is not hitting the exchange server, but you say that you have firewall logs suggesting that it is?

Which is correct?  I still think it is a external mailserver somewhere.

You really need to find out more specifics about the bounce. message (where it is being generated in particular).


Commented:
Was there a solution found to this? Can you clarify if so?

Thanks

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