[Dovecot] Using Dovecot as Asterisk PBX voicemail server

[Kenneth Porter]

I'm reading the Asterisk book, 2nd edition, and it describes how one can 
set up voicemail to be delivered by IMAP to a voicemail folder. Asterisk 
can monitor flags on the folder so that the "message available" light on 
one's phone tracks the state of the "read" flag in the folder. One can 
either dial in for one's voicemail or listen to it from one's favorite IMAP 
client. (Dovecot is mentioned in the book.)

I'm wondering how one would set up auth for this? Asterisk needs to log in 
to the account to deliver the voicemail and to check its state, but I 
wouldn't want to put everyone's mail password in plaintext in Asterisk's 
voicemail.conf file.

Would I set up a separate IMAP account for each user to hold their 
voicemail, and use simple passwords (such as the PIN they use for phone 
access to voicemail) in the Asterisk config? Or is there a way to set up 
Dovecot to allow a second user to login to a specific IMAP folder in all 
accounts, in the same way the local delivery agent has write access to all 
users' mailbox?

Google's page for the book:

<http://books.google.com/books?id=vtQxJ3oSm64C&dq=asterisk+book>

Dovecot mentions:

<http://books.google.com/books?id=vtQxJ3oSm64C&dq=asterisk+book&q=dovecot#search>