Email address domain not found (OWA setup)

Question

We have an in-house exchange server (SBS 2008) and have had 5 users successfully using blackberries for close to a year via setting up the OWA (outlook web access) at nextel.blackberry.com.
2 days ago one of the users upgraded his blackberry and email stopped working (both peronsal POP email as well as exchange email through OWA).
We deleted all the accounts at the nextel.blackberry.com website and tried to re-add them.  The personal MSN POP3 email was added successfully and is working great.  However when we try to add the account for OWA access, we get the error message "Email address domain not found".
Now I know that message comes up initially if you enter a password on the first screen.  But we still get this message on the advanced OWA setup screen.  We spent 2 hours on the phone with both nextel AND RIM and all either could tell us is that something must be wrong with our exchange server. (they were not able to add it either).
Well, our exchange server is running strong sending and receiving emails, we have several users throughout the country accessing OWA without ANY problems AND we have 4 blackberry users that are still active and receiving emails from our exchange server without any problem.
Any thoughts?  FYI we are running through postini for inbound/outbound email BUT this has never posed an issue previously for all the blackberries setup in the past year.

Answer 1

I was able to resolve this on my own.  Apparently Blackberry's website app scans for what it considers to be valid MX records on the domain of the email address you're trying to send.  We use postini for inbound/outbound and as a result had no MX records that pointed directly to our server.
When I added an additional MX record pointing directly to our server, blackberry's website was then able to add the account.  After the account was added I was then able to remove the MX record and the blackberry continues to function.