Exchange 2010 Mailbox move error “Strings that includes ‘@’, where ‘@’ cannot be the last character”
When migrating a mailbox to Exchange 2010 i came across an issue, where every time i tried to move the specific mailbox i got the below error.
Property Expression “User name” isn’t valid. Valid values are : Strings that includes ‘@’, where ‘@’ cannot be the last character.
Resolution
The username i was trying to move did not have an @ sign in his name so i didn’t see why this was failing, so this prompted me to look at the users account in AD.
I viewed the properties of the user account and then i checked the account tab, and i spotted there was no domain name specified in the user login name, which would explain why exchange was seeing it as “username@” so i added the domain entry in and then retried the move via exchange and it worked fine 
Hope this helps.
Daniel Davies
I wanted to THANK YOU for this post. It helped me immensely!
Thanks for posting this, I had the exact same problem, and you saved me a lot of time!
Thank you so much! This helped me immediately on 3 corrupted mailboxes!
Thanks
Thanks so much! Saved me a ton of time as well.
really helpful..
Thank you so much!
This was a great help Daniel, it solved the problem in over 20 accounts.
helped me heaps
This really helps and save us tons of time to find out why last two mailboxes couldn’t be moved. thanks a lot!
thanks a million, this helped me heaps. keep the great week.
Worked like a charm. Thanks for posting this.
Thanks for the tip. I had 50+ so decided to handle to handle this in PowerShell.
To find the accounts:
Get-ADUser -Properties * -Filter * | ? {$_.UserPrincipalName -NotMatch “@” }
Then pipe the results to set-aduser, here i concatenate the SamAccountName with your UPN suffix:
Set-ADUser -UserPrincipalName ($_.SamAccountName + “@yourdomain”)
Regards,
jfrmilner
Thank you, helped greatly!
Count me another that was helped by this, thanks!