3300 ICP - send to voicemail for call forwarding extension when no pickup?

[autoint]

We have a 3300 ICP running 9.0.0.41.
Let's say we have users A and B. When A is on vacation, they setup call forwarding to forward calls to B.
If B is on another call or away from their desk and doesn't pick up, calls go to A's voicemail.
We would instead like to make it so these forwarded (not picked up) calls go to B's voicemail.

This topic on the Spiceworks Community indicates this is possible. From the response marked Best Answer, "put that extension as the 1st alternative in the call rerouting assignment form." ("that extension" meaning the extension to forward calls/voicemail to)

So, I've tried this. On the Call Rerouting Assignment form, I clicked Change Page for the number associated with A, and plugged in the extension/number for B in the Call Rerouting - 1st Alt field. With that configuration, when I call A's extension, it rings and rings and rings...
I reverted the Call Rerouting - 1st Alt setting. On the Call Rerouting First Alternative Assignment form, I selected an unused entry and clicked Change Page. I entered B's extension in the Directory Number field and clicked Save, but I see the error, "[tt]The directory number is not allowed.[/tt]" I thought I could do this, then plug in the number for the Call Rerouting First Alternative Assignment form/entry in question, into the Call Rerouting - 1st Alt field of the Call Rerouting Assignment form for A.

Do you know if the problem is our software version? Something I missed/misunderstood? A workaround/other way to accomplish the same goal?

Thank you!

 

[kwbMitel]

The system is working as designed and there are ways to break the integration but all have some faults.

The simplest method is to use an intermediary extension to force the call to route differently and forge the originally dialed extension. This method uses Nametag Hunt groups. Caveat! - Once you use a Nametag huntgroup the call is FOREVER associated with the group. If the target voicemail will be the last destination of the call, then all will be fine. However, if the caller dials zero, or some other extension and is transferred elsewhere on the system it will ALWAYS return to the Nametag associated mailbox

Using your example
Create a Huntgroup with no menbers and assign the type - Nametag
The huntgroup extension will be *B (star followed by B's extension)
Forward (Or Route) extension A to the Nametag Group.
Use the Always Routing Alternative to route the Nametag Group to Extension B, with a 1st alternative of Voicemail

Calls to A will forward to *B which will Route to B and if unanswered end in B's VM

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