sendmail 관련 질문 입니다.

============== Relay 열지 않았을때 maillog ==========================================
May 23 14:50:28 web3 sendmail[11528]: j4N5oSeF011528: ruleset=check_rcpt, arg1=<house2013@nate.com>, relay=[222.239.136.118], reject=550 5.7.1 <house2013@nate.com>... Relaying denied. IP name lookup failed [222.239.136.118]

============== Relay 를 열었을때 maillog ==========================================
May 23 14:52:50 web3 sendmail[11608]: j4N5qnnC011606: to=<house2013@nate.com>, ctladdr=<house@usefulflower.com> (502/502), delay=00:00:01, xdelay=00:00:01, mailer=esmtp, pri=133193, relay=smtp.nate.com. [203.226.255.61], dsn=2.0.0, stat=Sent (Message accepted for delivery)

=============== 25  포트 접속 테스트 =========================
[root@web3 root-웹서버서브3,233]# telnet 220.90.215.233 25
Trying 220.90.215.233...
Connected to 220.90.215.233 (220.90.215.233).
Escape character is '^]'.
220 web3.flower1577-3535.com ESMTP Sendmail 8.13.4/8.12.11; Mon, 23 May 2005 15:38:04 +0900
ehlo localhost
250-web3.flower1577-3535.com Hello [220.90.215.233], pleased to meet you
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-8BITMIME
250-SIZE
250-DSN
250-ETRN
250-AUTH GSSAPI DIGEST-MD5 CRAM-MD5
250-DELIVERBY
250 HELP

[root@web3 root-웹서버서브3,233]# telnet 220.90.215.233 25
Trying 220.90.215.233...
Connected to 220.90.215.233 (220.90.215.233).
Escape character is '^]'.
220 web3.flower1577-3535.com ESMTP Sendmail 8.13.4/8.12.11; Mon, 23 May 2005 15:56:08 +0900
auth login
504 5.3.3 AUTH mechanism login not available

==============  sendmail cf ====================================================
# list of authentication mechanisms
#O AuthMechanisms=EXTERNAL GSSAPI KERBEROS_V4 DIGEST-MD5 CRAM-MD5

보시다 시피 sendmail.cf 파일의 Auth 부분이 주석처리 되어 있습니다.
그런데 250-AUTH GSSAPI DIGEST-MD5 CRAM-MD5 란 메세지가 뜹니다.
이 상황에서는 access 수정을 통해 보내기 받기가 잘 됩니다.

==============  sendmail cf 의 주석을 해제하고 LOGIN PLAIN 을 추가했을경우 =================
# list of authentication mechanisms
O AuthMechanisms=EXTERNAL GSSAPI KERBEROS_V4 DIGEST-MD5 CRAM-MD5 LOGIN PLAIN

이렇게 하고 restart 했을 경우에는 클라이언트(OUTLOOK)에서 "서버에서 사용자 이름과 암호를 받아들이지 않으므로 보내는 메일 서버(SMTP)로 연결하지 못했습니다" 라는 메세지가 뜹니다.

==============  sendmail cf 의 주석을 해제하고 LOGIN PLAIN 을 추가했을경우  25 포트 접속 테스트 ========
[root@web3 root-웹서버서브3,233]# telnet 220.90.215.233 25
Trying 220.90.215.233...
Connected to 220.90.215.233 (220.90.215.233).
Escape character is '^]'.
220 web3.flower1577-3535.com ESMTP Sendmail 8.13.4/8.12.11; Mon, 23 May 2005 15:49:46 +0900
ehlo localhost
250-web3.flower1577-3535.com Hello [220.90.215.233], pleased to meet you
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-8BITMIME
250-SIZE
250-DSN
250-ETRN
250-AUTH GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN
250-DELIVERBY
250 HELP

[root@web3 root-웹서버서브3,233]# telnet 220.90.215.233 25
Trying 220.90.215.233...
Connected to 220.90.215.233 (220.90.215.233).
Escape character is '^]'.
220 web3.flower1577-3535.com ESMTP Sendmail 8.13.4/8.12.11; Mon, 23 May 2005 15:55:13 +0900
YWRtaW4=
500 5.5.1 Command unrecognized: "YWRtaW4="
auth login
334 VXNlcm5hbWU6
YWRtaW4=
334 UGFzc3dvcmQ6
d25zZHlk
535 5.7.0 authentication failed

==============  sendmail cf 의 주석을 해제하고 LOGIN PLAIN 만 남겨둔 경우 =================
# list of authentication mechanisms
O AuthMechanisms=LOGIN PLAIN

[root@web3 root-웹서버서브3,233]# telnet 220.90.215.233 25
Trying 220.90.215.233...
Connected to 220.90.215.233 (220.90.215.233).
Escape character is '^]'.
220 web3.flower1577-3535.com ESMTP Sendmail 8.13.4/8.12.11; Mon, 23 May 2005 15:52:15 +0900
ehlo localhost
250-web3.flower1577-3535.com Hello [220.90.215.233], pleased to meet you
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-8BITMIME
250-SIZE
250-DSN
250-ETRN
250-AUTH LOGIN PLAIN
250-DELIVERBY
250 HELP

[root@web3 root-웹서버서브3,233]# telnet 220.90.215.233 25
Trying 220.90.215.233...
Connected to 220.90.215.233 (220.90.215.233).
Escape character is '^]'.
220 web3.flower1577-3535.com ESMTP Sendmail 8.13.4/8.12.11; Mon, 23 May 2005 15:54:30 +0900
auth login
334 VXNlcm5hbWU6
YWRtaW4=
334 UGFzc3dvcmQ6
d25zZHlk
535 5.7.0 authentication failed

이렇게 하고 restart 했을 경우에는 클라이언트(OUTLOOK)에서 "서버에서 사용자 이름과 암호를 받아들이지 않으므로 보내는 메일 서버(SMTP)로 연결하지 못했습니다" 라는 메세지가 뜹니다.

rpm 으로 sendmail 을 설치하였습니다.
sendmail-8.12.11-4.RHEL3.1

클라이언트에서는 OUTLOOK 의 인증 필요 체크는 하였습니다.
어떤 설정을 더 보아야 할지 막막합니다.
조언 부탁드립니다.