dovecot - Mar 2014 - IMAP proxy with master user and CRAM-MD5 auth mechanism

Hello,

I would like to know if it possible to have a dovecot IMAP proxy frontend where
CRAM-MD5 can be used as auth mechanism (assuming I would be using a master
user/password on the dovecot IMAP backend/mailbox)? I have read a few times the
following http://wiki2.dovecot.org/PasswordDatabase/ExtraFields/Proxy page but
somehow it is still unclear to me if the IMAP proxy then needs to have all the
users and passwords in its proxy table in the database? Unfortunately there are
no examples for that case.

Also with this case scenario is it possible to store the users' passwords in
CRAM-MD5 format?

Any pointers or documentation to such a scenario would be great.

Thanks and regards
M.L.