# Asterisk Project : IMAP Voicemail Application Notes

Added by mdavenport , edited by mjordan on Aug 06, 2012

Since the primary storage mechanism is IMAP, all message information that was previously stored in an associated text file, AND the recording itself, is now stored in a single email message. This means that the .gsm recording will ALWAYS be attached to the message (along with the user's preference of recording format if different - ie. .WAV). The voicemail message information is stored in the email message headers. These headers include:

- X-Asterisk-VM-Message-Num
- X-Asterisk-VM-Server-Name
- X-Asterisk-VM-Context
- X-Asterisk-VM-Extension
- X-Asterisk-VM-Priority
- X-Asterisk-VM-Caller-channel
- X-Asterisk-VM-Caller-ID-Num
- X-Asterisk-VM-Caller-ID-Name
- X-Asterisk-VM-Duration
- X-Asterisk-VM-Category
- X-Asterisk-VM-Orig-date
- X-Asterisk-VM-Orig-time
- X-Asterisk-VM-Message-ID

Upgrade Notice

The X-Asterisk-VM-Message-ID header is new in Asterisk 11. Existing voicemail messages from older versions of Asterisk will have this header added to the message when the messages are manipulated by app_voicemail in Asterisk 11.