Outlook Web App provides the functionality to change passwords that haven’t expired yet. However, if a password has already expired or is required to be changed at the first sign-in, the password can’t be changed via Outlook Web App unless you make a configuration change on the Client Access server to enable changing expired passwords.
- Log on to the Client Access server.
- Start Registry Editor (regedit).
- Locate the following registry subkey: 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.
- Exit Registry Editor.
Also the default “Minimum password age” is set to 1 day in Group Policy.