My Presto Mailbox is located in an assisted living facility with a shared phone system. To dial out you dial 9 followed by the number. The Mailbox worked for several months and then was unable to dial in. The problem appears to be that the 9,, dialing prefix causes a wait that results in an offhook signal from the phone system. Dialing that state is pointless. Is there a way to set the dialed number desired to include the 9 (e.g. 918667097978)? I cannot understand how it worked before as no changes to the phone system (that I can ascertain) have occurred.