Question : BESX 5.0.1.4 and Exchange 2010 Users can't activate enterprise email

I see the ETP.DAT file in the user's mailbox and opening it shows the email and carrier name but it's never deleted and activated.

When I check IMEStest in the utilities I see everything is fine except for:

Failed to check Active Directory for Send As permissions (80070057)

I made user the user has Send-As rights with the besadmin user

Answer : BESX 5.0.1.4 and Exchange 2010 Users can't activate enterprise email

Turns out the BESX server was running Windows 2008 R2 which isn't supported. I changed it to Win2003 and it works fine with the same accounts.