I have an issue here. My company using Exchange Server 2010 and AD 6 A user domain account is created by Oracle software in AD e.g. JohnS. Then I created mailbox with email address using existing the user account (user logon name). Later we found user has another domain account he use daily also named SmithJ. We discussed with him decide keep SmithJ to match company naming. Then we need use SmithJ as his mailbox related user account (user logon name). Questions are how to change user logon name for an existing mailbox? After change, he can access his mailbox for outlook when he login as SmithJ not JohnS (which he login before to access his mailbox and will not lost his all message in mailbox. Thanks in advance

Depending on how many users is in question. If just the one user then you can go into EMC -> recipient configuration -> users. Properties of the user -> general tab and change the alias from JohnS to SmithJ. What this will do is issue the user with another email address called smithj@domain.local and set it as the primary email address. Also it will leave the previous email address there as a secondary.

Yes, There is no harm todo this, Only you need to allow some time for replication and then check from outlook/OWA. How To Easily Change a User’s Exchange Server Alias and Display Name: http://technet.microsoft.com/en-us/magazine/dd560711.aspxAnil MCC 2011,ITIL V3,MCSA 2003,MCTS 2011, My Blog : http://messagingschool.wordpress.com

Hello Jack, Any update? Did Michael's suggestion work for you? Best Regards!Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.