Your system administrator can set up to 3 transfer numbers for your mailbox. When a caller to your mailbox presses 0, 2 or 3, the system transfers them to the matching number configured by your system administrator. Typically, this feature allows the system to transfer callers to the receptionist or one of your colleagues.
Contact your system administrator to find out if they have set any transfer numbers for your mailbox. When this feature is set, remember to alter your mailbox greeting in order to inform callers of the options they can use.