Definition: The voicemail is a method of recording and storing audio messages in that circumstances when the caller can't reach the called person.
(it can be activated if the caller party is busy, or at no answering situations or even permanently)
The called persons can playback anytime later these audio messages by just calling the extension number which is assigned to his voicemail.
Also in some VoIP servers the recorded voice files can be sent automatically to the users email address.

How to setup voicemail?

In the Mizu softswitch the users can check their voicemail by dialing the 5000 or 5001 extension numbers.
Once the users arrives to the voicemail IVR, they are able to listen their messages and after it the messages can be deleted or stored.
Some VoIP servers requires authentication (pin code or password) for the voicemail access, other VoIP servers doesn't.
The voicemail related configurations in the Mizu VoIP server can be found at MizuManage/ users and devices/ Endusers/ Functions/ Voicemail section.
In the Mizu universal webphone the voicemail number can be set with this parameter: voicemailnum
 (this number will be called by the user to hear his messages) 

Benefits of voicemail service:
-improves the public relations in companies: the voicemail services can be used at any hour of the day, also in weekends and holidays.
The customers will apreciate that they can leave a message at anytime regarding their issue or requirement.
-it can reduce the need of receptionist support

Disadvantages of the voicemail:
-some people don't like at all if they can't discuss a live person, especially if they have an urgent issue
-in case that you miss a large amount of calls, it can be tiring to listening them
-voicemail systems can be a good target of hackers, who can find your personal informations if they hacks your password
-if you have a small business, the costs of a voicemail system can be to high for your budget