A device in a provider network receives a Session Initiation Protocol (SIP) request message from an originating device, where the SIP request message includes a general number for a voicemail service and where the voicemail service includes multiple voicemail systems. The device determines whether the originating device is associated with a voice-over-Internet-protocol (VoIP) account on the provider network and, when the originating device is associated with a VoIP account, selects a direct access number assigned to a voicemail system, from the multiple voicemail systems in the network, that services the VoIP account. The device also associates the direct access number and the SIP request message, and forwards, based on the direct access number, the SIP request message to an application server.