We run
Binc IMAP since it's fairly simple, and it talks maildir by default. It uses
daemontools.
We do a build from the source, with the default installation locations; no configuration is needed. (We had to hack the sources, though: look for "extern int errno;" and replace it with "#include <errno.h>".) The build needs
gcc-c++ and
openssl-devel.
The package can be built as a non-privileged user. Follow the instructions, and do a "make testcert" to get a test certificate for SSL connection.
There's an error in the documentation: the daemontools templates are in
/usr/local/var/service, not
/usr/local/share/service. Also, for some reason,
/usr/local/var/log (the default log location) is not created, so we do that by hand.
The authentication machinery needs
checkpassword.