Voicemail-/Fax Box
Proceed as follows:
Separately for profiles
Using the Configuration Manager
Profile-related (page Groups > Profiles > Configuration > Configure)
PROFILE CONFIGURATION 
Select the profile you want to display/configure.
Function-related (page Groups > Profiles > Function overview)
Configure
Opens the configuration of the single function for all profiles.
Profile-controlled settings
The profile setting overrides the group setting.
* Note: When switched off, the setting under Groups > Properties applies.
Voice mailbox       Call acceptance type
                               on all logged out
                             Delay time for CF on no reply
immediately
The voice mailbox will be called immediately.
on no reply
The voice mailbox will be called after expiration of the entered delay time.
on busy
The voice mailbox will be called if the internal number of the subscriber is busy and if no call forwarding on busy has been enabled for the subscriber.
on no reply + on busy
The voice mailbox will be called if the subscriber does not reply or if the internal number of the subscriber is busy.
The voice mailbox will be called if all group members are logged out.