I have used Courier IMAP at home since a long time. As I want to update a dovecot 1.2 setup to dovecot 2.x, I decided to first have a look at dovecot 2.x at home.
Switching from Courier IMAP to dovecot is really easy. I just configured the correct path to the maildir, setup a passdb/userdb, and it was working.
The important part was the correct transfer of the passwords. I used already an userdb in Courier IMAP with MD5 passwords. For each user it has imappw=XXX with XXX similar to $1$abc.
This can be converted into a dovecot passdb/userdb line very easily:
username:{MD5-CRYPT}$1$abc::UID:GID::HOMEDIR::userdb_mail=maildir:~/path/to/maildir
The corresponding passdb/userdb settings for dovecot are:
passdb {
args = scheme=MD5-CRYPT username_format=%u /usr/local/etc/dovecot/dovecot.pws
driver = passwd-file
}
userdb {
args = username_format=%u /usr/local/etc/dovecot/dovecot.pws
driver = passwd-file
}
Compared to when I had a look the last time, dovecot is also able to use OTP as an authentication mechanism now. Unfortunately I did not find any documentation how to configure/use it.
Incidentally, I just switched to archiveopteryx (after looking at dovecot) and was, well, astonished, at how easy it was: make install, run installer, change config to forbid plain logins and voila: a fast imap and smtp submission server with allmost no configuration! Since I used dbmail before, I could transfer users with some simple sql hacking…