Yes, Postfix is only an MTA. If you want POP or IMAP, you need to install a separate daemon, like qpopper.
Here's some notes on qpopper that I wrote awhile back...
Installing qpopper
tar zxvf qpopper4.0.4.tar.gz -C /usr/local/src
cd qpopper4.0.4
./configure --enable-specialauth
# specialauth enables shadow passwords.
make
# copy the popper executable anywhere you want, below is the default
cp popper/popper /usr/sbin/
chmod 700 /usr/sbin/popper
# optional…
make clean
make realclean
Configuring qpopper to use xinetd
Create the /etc/xinetd.d/popper file and put this in it…
service pop3
{
disable = no
flags = REUSE
socket_type = stream
wait = no
user = root
server = /usr/sbin/popper
log_on_failure += USERID
}
…and remember to restart xinetd with "/sbin/service xinetd restart"
ChrisP