Aastra M401 User Manual page 29

6.2.1 Immediate call forwarding
To forward all your calls immediately to your voice mailbox.
On your keypad:
Press the following keys consecutively
You will hear two beeps.
Hang up.
6.2.2 Forwarding your calls on no answer
To forward all your calls to your mailbox automatically after several rings.
On your keypad:
Press the following keys consecutively
You will hear two beeps.
Replace the handset.
Calls forwarding
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