Voicemail (or voice mail, vmail or VMS) is a centralized system of managing telephone messages for a large group of people. In its simplest form it mimics the functions of an answering machine, uses a standard telephone handset for the user interface, and uses a centralized, computerized system rather than equipment at the individual telephone. Voicemail systems are much more sophisticated than answering machines in that they can:
- answer many phones at the same time
- store incoming voice messages in personalized mailboxes associated with the user's phone number
- enable users to forward received messages to another voice mailbox
- send messages to one or more other user voice mailboxes
- add a voice introduction to a forwarded message
- store voice messages for future delivery
- make calls to a telephone or paging service to notify the user a message has arrived in his/her mailbox
- transfer callers to another phone number for personal assistance
- play different message greetings to different callers.
Voicemail messages are stored on hard disk drives, media generally used by computers to store other forms of data. Messages are recorded in digitized natural human voice similar to how music is stored on a CD. To retrieve messages, a user calls the system from any phone, logs on using Touch-tones (clearing security), and his/her messages can be retrieved immediately. Many users can retrieve or store messages at the same time on the same voicemail system.
Many voicemail systems also offer an automated attendant facility. Automated attendants enable callers to a "main" business number to access directory service or self-route the call to various places such as a specific department, an extension number, or to an informational recording in a voice mailbox, etc.