Courier and Cyrus Sasl have been removed and substituted with Dovecot which now
handle authentication for Postfix, Imap and Pop3, with support for SSL.
This allow the use of several encryption schemes for the password as well as a
single user db.
OpenDKIM keys can now be provided at the startup and will be used instead of
generating new ones (so that you don't have to change your DNS configuration).
This version builds correctly on Docker but no integration tests have been
reworked to accommodate Dovecot instead of Courier and Cyrus Sasl. As such
at present no automatic tests can be executed.
