Here is the scenario... Exchange 2007 with not all user in the domain having Exchange mailboxes. One night I attempt to migrate a user to Exchange. Here is what happened (in brief): 1) Disable-mailuser 2) Enable-mailbox 3) Attempt to migrate mail from external IMAP server... this Fails 4) Begin reverting account 5) Disable-mailbox 6) Enable-mailuser 7) Add X500 address 8) Check things. About a week later I discover one of my co-workers sent this user a message and got a bounce because his cache entry for this user had changed to IMCEAEX-_O=<orgName>_OU=First+20Administrative+20Group_cn=Recipients_cn=<username>21777426@<domain> (add substitutions for entries in <>) The migration bumble took about 1hour (11pm-midnight) but everything was set at the end. Looking at the account now (days later) and the entry looks right. Does anyone know why/how this happened for this entry? Is there any documentation on Outlook cached entries getting messed up by the server? Thanks, Gene

Hi, This problem could be caused by the local Nk2 file which contains the saved AutoComplete names and the address cache. Try to empty auto complete list in Outlook: 1. Open C:\Users\YourUserName\AppData\Roaming\Microsoft\Outlook, copy the outlook.nk2 file to another folder as a backup. Rename it to outlook.old. If you are using Windows XP or 2003, please go to the following folder: C:\Documents and Settings\"youruser"\Datos de programa\Microsoft\Outlook 2. Restart Outlook. Then test to see if the issue persists. 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. Thanks Gen Lin-MSFT

At step 7, when you added the X500 address, did you add what was the Mail User's LegacyExchangeDN, i.e. result of (Get-Mailuser username).LegacyExchangeDN ? Steve Goodman Check out my Blog for more Exchange info or find me on Twitter

On Mon, 15 Nov 2010 06:16:04 +0000, Gen Lin wrote: >This problem could be caused by the local Nk2 file which contains the saved AutoComplete names and the address cache. That's true up to Outlook 2010. > Try to empty auto complete list in Outlook: To do this in OL2010, use "File | options| Mail | Empty Auto-Complet List". --- Rich Matheisen MCSE+I, Exchange MVP --- Rich Matheisen MCSE+I, Exchange MVP