Asterisk: The Future of Telephony, 2nd Edition

Alternative Voicemail Storage Methods

Asterisk’s normal way of storing voicemail is to simply record the message in a file, which is placed on the local hard drive under the /var/spool/asterisk/voicemail tree. While this works well enough for simple PBX deployments, there are more advanced ways of doing this that can be very useful in larger, distributed networks, or environments where tighter integration with external applications is desired.

Storing Voicemail in an IMAP Server

The ability to store voice messages in the same location as regular email is something that the telecom industry has been promising for a long time. They called it Unified Messaging, and while most PBXes now offer some sort of unified messaging, it is typically very expensive to license and implement.

Naturally, Asterisk cuts through all the silliness and just allows you to have your voicemailbox integrated into an IMAP environment. There are several advantages to storing your voicemail on an IMAP server. When you listen to a voicemail on your phone, the message is set to the read state on the IMAP server. This means that your email client will also note that it has been read. By the same token, if you listen to the message from your email client, the voicemail will turn off the message notification light on any phones that are assigned to that mailbox. Deleting a message from one place will cause it to be deleted from every place. So once deleted, the message is truly gone. This is Unified Messaging, the holy ...