I have an Avaya PartnerMessaging R7.0 system with 3 incoming lines. The way it is set up right now, lines 1 & 2 go to the automated attendant, and line 3 is a direct extension transfer to extension 18. When the user is on extension 18, callers who dial in via the number for line 3 get a busy signal, but callers who dial in via line 1 or 2 and then select extension 18 will get the voicemail for extension 18, if extension 18 is in use.

Is there a way to set it up so that callers who dial directly via line 3 will get voicemail if extension 18 is in use?