This is what i get when i try to set up an Exchange 2007 mailbox on outlook 2007 using autodisover….

I tested with manually setup – exact same issue. this _was_ weird cause its normally not  problem, added plenty of users in the past.

after spending some time searching on google i found out that theres multiple scenarios that can cause this – none of which made any sense in my case.

after comparing some users, i found out i had “forgotten” to add the custom attribute to the mailbox. We use this cause we are using shared hosting – hiding each customer/company from eachother in the address book.

http://www.msexchange.org/articles_tutorials/exchange-server-2007/migration-deployment/shared-hosting-exchange-2007-part1.html

after applying it, i saw the user came up in the address list under that ou, and everything seems to work now :)