몇날 해메다가 겨우 해결책을 찾았습니다.
 /sbin/chkconfig --list ipop3
ipop3        off
 기본적으로 이렇게 되어있더군요.
 그래서
 /sbin/chkconfig --level 345 ipop3 on
했더니
ipop3     on
 telnet localhost 110
OK Pop3 Ready..
 에고 겨우 찾고 나니 정말 황당하군요.
 혹시 더 좋은 방법 아시면 알려주세요
 : my system dosn't allow HANGUL.
: sorry.
:
: I don't know why pop3 service doesn't start.
:
: sendmail runs perfectly, and port 25 is open.
: but pop3 service doesn't start.
:
: I use Redhat 7.0 pkged by Wow.
:
: I installed imap package rpm files,
: and have ipop3d under /usr/sbin/
: and config file ipop3 under  /etc/xinetd.d/
:
: I edited /etc/services file, and uncomment pop3 line.
:
: I added my domain and aliases to /etc/mail/local-host-name, and
: even made /etc/sendmail.cw including my domain info.
:
: DNS and MX record is set like this..
:
:                 IN      NS      ns.mydomain.co.kr.
:                 IN      A       210.xx.xx.85
: localhost       IN      A       127.0.0.1
: ;
:                 IN      A       210.XX.XX.85
: ns              IN      A       210.XX.XX.85
: www             IN      A       210.XX.XX.85
: mail            IN      A       210.XX.XX.85
: mydomain.co.kr.    IN      MX 10   mail.mydomain.co.kr.
:
:
: If i manualy start /usr/sbin/ipop3d, it works but only in the session.
: But telnet localhost 110 is not work!
: What's wrong? and what should i find?
: Let me know , thanks.--이 곳에 서명을 적어주십시오.
"시로요"