The dkimap4 and dkpop3 daemons should be invoked by your /etc/inetd.conf file
with lines such as:

pop3	stream	tcp	nowait	root	%%PREFIX%%/libexec/dkpop3	dkpop3
imap4	stream	tcp	nowait	root	%%PREFIX%%/libexec/dkimap4	dkimap4

You also need to set up PAM properly, as PAM is enabled by default. Use
something like this in /etc/pam.conf:

pop3	auth	required	pam_unix.so
pop3	account	required	pam_unix.so	try_first_pass
imap	auth	required	pam_unix.so
imap	account	required	pam_unix.so	try_first_pass