Patent ID: 8064367

Claim:
A method, comprising: at a Session Initiation Protocol (SIP) based Internet Protocol private branch exchange (IP PBX), receiving an event notification message from a user agent corresponding to a voicemail system from a service provider, said event notification message comprising a Request-URI field identifying a Uniform Resource Identifier (URI) of the SIP based IP PBX and a header field identifying a target mailbox from a plurality of target mailboxes associated with a single account between the service provider and the SIP based IP PBX having a single user identifier and a single password with a single address registered with the service provider; identifying a URI corresponding to the target mailbox; and forwarding the event notification message with a Request-URI field identifying the URI corresponding to the target mailbox, wherein the service provider sends the event notification message to a primary SIP Uniform Resource Locator (URL) for the single account each time at least one of the plurality of target mailboxes experiences a change in status and wherein the service provider only maintains one account to service the SIP based IP PBX with different mailbox identifiers for each mailbox within the one account.