hello everyone

pkg/README-server:
By default, the Dovecot processes run in the login(1) class of "dovecot".

pkg/PLIST-server:
@newuser _dovecot:518:_dovecot::Dovecot Account:/nonexistent:/sbin/nologin
@newuser _dovenull:666:_dovenull::Dovecot Login User:/nonexistent:/sbin/nologin

cheers
nathanael