Voicemail (or voice mail; abbreviated v-mail or vmail) is a specific application of an interactive voice response system. In its simplest form it mimics the functions of an answering machine, but uses a centralised system rather than equipment at the individual telephone. However it can be far more sophisticated, with the ability to forward messages to another voice mailbox and send simultaneous messages to multiple voice mailboxes, add voice notes to a message, store messages for future delivery, make calls to a telephone or paging service when a message is received, transfer callers to another phone for personal assistance and play different message greetings to different callers.

Many voicemail systems also offer an automated attendant facility, allowing callers answered by the system to dial a selected person's mail box or telephone.

Voicemail systems are found associated with many office telephone systems or (PBX). They may also be associated with public telephone lines as network services. Mobile phones generally have voicemail as a standard network feature.