Call Forward lets you redirect incoming calls to an alternate number.

Select the following option:
• Always redirects all incoming calls regardless of the state of your telephone.

To program Call Forward:
1. Press (MENU).
2. Press # or the No softkey until "Call Forwarding?" appears.
3. Press * or the Yes softkey .
4. Press # or the Next softkey until the type of Call Forward that you want to set up appears (Always).
5. On a 5324 IP Phone only, press * or the Review softkey.
6. If a number is already programmed, press * or the Change softkey .
7. Press * or the Program softkey .
8. Dial the destination number.
If you make an error while dialling, press * or the softkey to correct errors.
9. Press (DOWN) or the Save softkey.

FORWARDING PHONE CALLS

When you forward calls, it will ring through to the forwarded number.  If no one answers, the ORIGINAL number's voicemail picks up.

The only other suggestion is to have the extended absence message in place, so that they cannot leave a voice message at that extension, and redirect them to the correct number to call.