I should be clearer.

I have Centrex lines for the users that forward into a Centrex hunt group that is connected to the Key Voice system 1 line per port IE 25 lines. I use call forward directory option on Centrex to provide the SMDI routing digits so the call will go to a specific mailbox.

For example: You dial 555-4567 on busy no answer to forwards to 222-5000 (this would be the lead hunt group number) The switch sends a signal to voice mail so it goes to box 4567. It works most of the time but then sometimes it will go to the main system greeting (this is the default if the SMDI is not recognized.) It gets worse the busier the system gets. When I watch it on the Line status monitor it says, “wait caller id” Then it routes out to the main greeting instead of the correct individual’s mailbox. If you unplug the SMDI it will route to the main greeting on every call. IE no SMDI it will route to the main greeting by default.