Applies to: Exchange Server 2010
Enable change password feature in Outlook Web App:
Log on to the Client Access server.
Open Registry Editor
regedit
Find registry key
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchange OWA
Create the following DWORD value if it doesn't already exist: ChangeExpiredPasswordEnabled. The value type will be REG_DWORD
Set the value of ChangeExpiredPasswordEnabled to 1
Restart IIS
iisreset /noforce
Note:
You must make this change on each Client Access server that supports Outlook Web App