Hello All, We used to be under our parent company. About 6 months ago we migrate to Exchange 2010. Newly created mailboxes do not have x500 addresses, but the one that got migrate do. Is it safe to delete X400 and X500 addresses? Thanks, Yassar

Hi Yassar I would certainly leave the X500 addresses alone as these would have maintained calendar appointment ownership and the nickname cache in Outlook. These X500 addresses are actually made from the legacyExchangeDn of the original source mailbox. Cheers, Steve

Steve is right. As far as x400 addresses if you're natively 2010 yes x400s can be deleted. There's many ways to delete, heres one using admodify i blogged years back. http://msexchangetips.blogspot.com/2008/01/exchange-bulk-remove-x400-address-using.htmlJames Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com