Problem with sub domain mail classed as relay

[davetherave100]

Hi
We have a domain of xyz.ac.uk. All our users have a mailbox on the one exchange 2000 server.
The users are basically split into two groups.
If any user has an email of username@xyz.ac.uk mail works fine in and out.
What i am wanting to do it to set the other half of the users to have an email of username@abc.xyz.ac.uk, as well username @xyz.ac.uk, but to make the abc.xyz.ac.uk the primary adress.
If a user has this email address, mail works ok internally and outoing, but any mail sent to the email addresses are rejected by the server and seen as a relay attempt.
I have put in an entry in the smtp virtual server to allow the domain offabc.xyz.ac.uk to relay throuh this server, and also an entry in global settings, internet message formats for the domain.
I must be missing something but havent found what yet!
Thanks

 

[jbud]

Does the hostname abc.xyz.ac.uk resolve to the exchange server?

 

[davetherave100]

Yeah, we have a child domain entry in our dns, with a mx record for and a host for thew mail server
We get a NDR from our mail server saying unable to relay, with a 5.7.1 error.
I can telnet to mailserver.abc.xyz.ac.uk and get a response
Any ideas?

 

[jbud]

I can't find the reference right now, but I believe Exchange has a problem routing mail when the name of the child domain resolves to the Exchange server. I think I read this in the Ex2000 SMTP guide.

Another good cursory check is to look at this:

http://support.microsoft.com/default.aspx?scid=kb;en-us;153001&Product=exch2k

If I find anything else, I'll post it.

 

[jbud]

I found what I was looking for in the E2K SMTP guide. The error I was thinking about is a 5.4.8. For 5.7.1, you should look at (quoting):

Possible causes include:
*General access denied, sender access denied — the sender of the message does not have the required permissions necessary to complete delivery.
*You are trying to relay your mail through another SMTP server,and the server does not permit you to relay.
*The recipient may have mailbox delivery restrictions enabled. For example,if a recipient ’s mailbox delivery restriction is set to receive mail from a distribution list only, non-member’s mail will be rejected and produce this
error.

Hope this helps.

 

[davetherave100]

Thanks for you help Jbud, having read some of the info from your links, it seems that it wont work the way im trying to make it.
Looks like ill have to give the users the email of user@xyz.ac.uk.
Thanks again