I have a customer with an MICS w/6.1 SW, and they have a night service set-up and they about 15 phones rings and then the General Delivery VM supposed to pick-up. What's happening is one particular ext's VM is picking up. I & the customer have cancelled DND and Call Fwd, and the phones ring as programmed. But then for no apparent reason that particular Ext's VM will pick up again. I've inquired if the user is forwarding her phone to the VM at lunch and after hours, or putting the phone in DND, and I'm told no. Temporarily I've taken that ext out of the ringing group to see what happens. I've even suggested that if not needed, leave that user out of the group all together. I'm open to suggestions.

Thanks

I would imagine it's the lowest numbered extension whose mailbox is picking up. See if you take away that extension's mailbox and see if the general mailbox picks up.

I would recommend a 'hunt group' for the night service
with 'hunt group mailbox assigned.

For test purposes, change that ext to fwd to VM after 12 rings.
If that works, then bring it back down to a more normal number of rings but still keep it higher than the others.