We recently moved to Office 365 and setup DirSync. I need to decommission our old SBS Exchange 2003 server. To uninstall Exchange, I am required to remove all mailboxes. However, when a mailbox is removed, it also removes the following attributes that O365 Dirsync relies on: mail, mailNickname, ProxyAddresses.
What is the best way to backup these settings and then restore them after I remove the exchange server?
(I swear I saw a power-shell script in another post, but for the life of me I can't find that post now)