Look in menu 1-1 and change the number of rings for on PBX calls used for outcalling. This should take care of it.
ACP Used for Integration: N
Type of PBX or Centrex VPMOD is on: A - NEC 2400 MMG/MCI
Number of Digits in Extension (Used for Outcalling and ECP): 4
Number of Digits in Extension (Used for Message Waiting): 4
Number of Rings for On-PBX Calls (Used for Outcalling): 4
Number of Rings for On-PBX Calls (Used for ECP): 4
Sender ID Used for Telephone Answering Messages: 2 - Calling Party, if Known
Saved Messages - Keep Date/Time Stamp of When the Message was Received: Y
Block Messages to Uninitialized Mailboxes (Y/N): N
ANI Used for Integration: Y
Ken Means