The different types of voicemail services can be defined based on the hardware they run on, the types of users they are designed for, or the feature sets they offer. Voicemail services can be set up on regular computer hardware, and these systems can even include voice board circuitry, switching devices and additional phone jacks, as necessary. The other way to set up voicemail services involves proprietary hardware that is built from the ground up. Different services use these two formats to provide voicemail to home and business users over landlines and also to cellphone users. Some of the features that different services can offer include multiple voicemail boxes, a number of pre-recorded messages that can provide useful or timely information, and integration with email or fax systems.
There are two main ways that voicemail services can be set up. One way involves specialized software running on regular computer systems. Some third-party service providers use this setup, though it is also common among businesses that offer their own in-house services. A simple example of this type of voicemail system can consist of a single computer and one phone line, though large corporate versions use networks of computers, multiple voicemail boxes and additional specialty hardware. Voice board circuitry, additional phone jacks and other hardware can be added to these systems to expand the available services.
Other voicemail services are based on proprietary hardware that is typically custom built on a case-by-case basis. Some companies build these systems to offer their own in-house solutions, though these systems are more commonly used by third-party providers. Voicemail services that are offered to home-based landlines and cellular phones usually use this format. These systems can often be larger and more feature-rich than software-based solutions that run on regular computer hardware.
Different voicemail services can also offer a range of features. Basic voicemail for home or cellular use typically includes a single mailbox that can be accessed using a personal identification number (PIN), though additional mailboxes are sometimes available. Business services often include a single main mailbox and then any number of additional boxes for the employees. Some of these business services also provide email or fax functionality, in which case a mailbox may be able to store faxes in addition to voicemail. Another variation is the question and answer or bulletin board voicemail system, which provides callers with a list of informational messages that can be listened to on demand.