sendmail 문제, 내부네트웍끼리는 이상없는데 외부네트웍으로 메일이 안갑니다.

첨부이미지는 저희집 네트웍 구조입니다.

네임서버 정보입니다.

ns # cat /etc/bind/named.conf
options {
directory "/var/bind";
dump-file "/var/bind/named_dump.db";
statistics-file "/var/bind/named.stats";
pid-file "/var/run/named/named.pid";
listen-on-v6 { none; };
};

zone "." IN {
type hint;
file "named.ca"; // linked root.cache
};

zone "localhost" IN {
type master;
file "pri/localhost.zone";
allow-update { none; };
notify no;
};

zone "127.in-addr.arpa" IN {
type master;
file "pri/127.zone";
allow-update { none; };
notify no;
};

zone "test.ac.kr" IN {
type master;
file "zone/test.ac.kr.zone";
allow-transfer { 1.1.2.200; };
notify yes;
};

zone "1.1.in-addr.arpa" IN {
type master;
file "zone/test.ac.kr.rev.zone";
allow-transfer { 1.1.2.200; };
};

ns # cat /var/bind/zone/test.ac.kr.zone
$ORIGIN test.ac.kr.
$TTL 86400
@ IN SOA ns.test.ac.kr. gogisnim.gmail.com. (
2007083003 ; serial
1H ; refresh
15M ; retry
1W ; expiry
1D ) ; minimum

IN NS ns.test.ac.kr.;
;
IN MX 10 mail
IN MX 20 mail2
;
; host configuration
localhost IN A 127.0.0.1
ns IN A 1.1.1.200
ns2 IN A 1.1.2.200
test.ac.kr. IN A 1.1.1.202
www IN A 1.1.1.202
mail IN A 1.1.1.201
mail2 IN A 1.1.2.201
pop3 IN A 1.1.1.201
fw IN A 1.1.1.10

ns # cat /var/bind/zone/test.ac.kr.rev.zone
$ORIGIN 1.1.in-addr.arpa.
$TTL 86400
@ IN SOA ns.test.ac.kr. gogisnim.gmail.com. (
2007083003 ; serial
1H ; refresh
15M ; retry
1W ; expiry
1D ) ; minimum

IN NS ns.test.ac.kr.;
;
;
; host configuration
200.1 IN PTR ns.test.ac.kr.
200.2 IN PTR ns2.test.ac.kr.
200.1 IN PTR test.ac.kr.
200.1 IN PTR www.test.ac.kr.
201.1 IN PTR mail.test.ac.kr.
201.2 IN PTR mail2.test.ac.kr.
201.1 IN PTR pop3.test.ac.kr.
10.1 IN PTR fw.test.ac.kr.

sendmail 설치를 이렇게 했습니다.

mail # useradd desk1
mail # useradd desk2
mail # passwd desk1
password: 1111
mail # passwd desk2
password: 2222
mail #
mail # emerge sendmail
mail # cd /etc/mail
mail # m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf
mail # cat /etc/mail/local-host-names
test.ac.kr
mail # cat /etc/mail/access
127.0.0.1 RELAY
localhost RELAY
localhost.domains RELAY
1.1 RELAY
mail # makemap hash /etc/mail/access < /etc/mail/access
mail # cat /etc/mail/aliases
mailer-daemon: postmaster
postmaster: root
desk1: desk1 # Desktop1 User
desk2: desk2 # Desktop2 User
mail # newaliases
mail # /etc/init.d/sendmail start
* Starting sendmail ... [OK]
mail #

courier-imap 설치를 이렇게 했습니다.

mail # emerge courier-imap
mail # /etc/init.d/courier-pop3d start
* Starting courier-authlib: authdaemond ... [OK]
* Starting courier-pop3d ... [OK]
mail #
mail # netstat -lnp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:25 0.0.0.0:* LISTEN 21522/sendmail: acc
tcp 0 0 0.0.0.0:587 0.0.0.0:* LISTEN 21522/sendmail: acc
tcp 0 0 :::22 :::* LISTEN 17951/sshd
tcp 0 0 :::110 :::* LISTEN 21642/couriertcpd
Active UNIX domain sockets (only servers)
Proto RefCnt Flags Type State I-Node PID/Program name Path
unix 2 [ ACC ] STREAM LISTENING 17443 21611/authdaemond /var/lib/courier/authdaemon/socket.tmp
unix 2 [ ACC ] STREAM LISTENING 11207 15491/syslog-ng /dev/log

이상이 네임서버, smtp, pop3 서버 설정이었습니다.
desktop1에 thunderbird 설치하고 desk1로 메일 보내고 받게 설정했습니다(인증해서)
desktop2에 outlook express 설치하고 desk2로 메일 보내고 받게 설정했습니다(인증해서)

desk1@test.ac.kr 에서 desk2@test.ac.kr로 메일 잘 가고 잘 받아집니다.
그런데 desk1@test.ac.kr에서 gogisnim@gmail.com(외부 메일)로 메일보내면 안갑니다.

syslog 입니다.

# tail -f /var/log/messages
Sep 4 00:08:16 mail sm-mta[21653]: l83F8Gv3021653: ruleset=check_rcpt, arg1=, relay=[1.1.1.50], reject=550 5.7.1 ... Relaying denied. IP name lookup failed [1.1.1.50
Sep 4 00:08:16 mail sm-mta[21653]: l83F8Gv3021653: from=, size=392, class=0, nrcpts=0, proto=ESMTP, daemon=MTA, relay=[1.1.1.50]

메일클라이언트의 에러메시지
받는 사람중 한 사람이 서버에서 거부되었으므로 메시지를 보낼 수 없습니다.
거부된 전자메일 주소는 'gogisnim@gmail.com' 입니다.
제목 'mail sending test to gmail ~~~', 계정: 'pop3.test.ac.kr', 서버: 'mail.test.ac.kr', 프로토콜: SMTP,
서버응답: '550 5.7.1 ... Relaying denied. IP name lookup failed [1.1.1.50]',
포트: 25, 보안(SSL): 아니오, 서버오류:550, 오류번호: 0x800CCC79

외부로 메일이 가야 정상아닌가요?
제가 착각을 하고 있는걸까요?