Thanks for the comment on my blog. I actually had problems with a similar script a couple years ago on Exchange 2000. The script SHOULD have worked, but it didn’t return all OWA-enabled accounts on Exchange 2000 at the time.

The accounts in question had the HTTP protocol enabled in AD Users and Computers, but they didn’t show up in the list generated by this query. I looked at the AD attributes using ADSIEdit - (or it could have been LDP) and the “HTTP” attribute actually didn’t exist, even though the option was definitely checked in AD Users and Computers. Anyway, I’d suggest spot checking a half dozen accounts that you know are enabled, just to make sure the script is giving you all the users.

My script use the Advanced Find feature in AD Users and Computers rather than dsquery, but as I said, the attributes were actually missing in AD.