릴레이 관련 질문입니다.

 안녕하세요.

 얼마전부터 다음, 파란 등의 포털 사이트로의 메일 발신이 되지않아 큐를 열어보니

엄청난 양이 쌓여있더군요. 릴레이는 분명 막아두었고 다시 한번 확인을 해보았지만

막혀있다는 메시지만 볼 수 있었습니다.  찾아보니 제로보드등의 결함을 이용해 대량의

메일을 릴레이 할 수도 있다고 하는데 jsboard에도 같은 문제가 있는것인지...

Mar  4 11:14:21 icapws sendmail[12168]: k229GKnn003216: to=<firepak@qwest.net>, delay=1+16:57:58, xdelay=00:00:13, mailer=esmtp, pri=3210380, relay=mpls-cmx-09.inet.qwest.net. [63.226.138.9], dsn=4.3.0, stat=Deferred: 451 http://dsbl.org/listing?221.161.131.55
Mar  4 11:14:22 icapws sendmail[12168]: k229GKnn003216: to=<firehawk@adelphia.net>, delay=1+16:57:59, xdelay=00:00:00, mailer=esmtp, pri=3210380, relay=mx.adelphia.net. [68.168.78.104], dsn=4.0.0, stat=Deferred: 421 Message Rejected. There are three possible causes for this rejection.  If your server ...e dropped. Otherwise, Please refer to www.spamhaus.org, dsbl.org and njabl.org for more information.
Mar  4 11:14:27 icapws sendmail[11044]: k220mVnn002138: to=<stjoan@charterpa.net>, delay=2+01:25:53, xdelay=00:01:00, mailer=esmtp, pri=3630380, relay=charterpa.net. [69.25.142.10], dsn=4.0.0, stat=Deferred: Connection timed out with charterpa.net.
Mar  4 11:14:27 icapws sendmail[11044]: k220mVnn002138: to=<stjoe@nnex.net>, delay=2+01:25:53, xdelay=00:00:00, mailer=esmtp, pri=3630380, relay=mail.nnex.net., dsn=4.0.0, stat=Deferred: Connection timed out with mail.nnex.net.
Mar  4 11:14:27 icapws sendmail[11718]: k2293Unn003174: to=<dharguess@coastline.edu>, delay=1+17:10:50, xdelay=00:03:00, mailer=esmtp, pri=3480380, relay=mail3.coastline.edu. [159.115.70.244], dsn=4.0.0, stat=Deferred: Connection timed out with mail3.coastline.edu.
Mar  4 11:14:28 icapws sendmail[11044]: k220mVnn002138: to=<stk811@optonline.net>, delay=2+01:25:54, xdelay=00:00:01, mailer=esmtp, pri=3630380, relay=mx2.optonline.net. [167.206.4.79], dsn=4.2.1, stat=Deferred: 452 4.2.1 Your host 221.161.131.55 has no DNS record . If you are using a firewall please configure DNS and try again authoritative host not found: stk811@optonline.net
Mar  4 11:14:28 icapws sendmail[11718]: k2293Unn003174: to=<dhartley@vbusinesssupport.com>, delay=1+17:10:51, xdelay=00:00:01, mailer=esmtp, pri=3480380, relay=mail.vbusinesssupport.com. [66.235.202.41], dsn=4.3.0, stat=Deferred: 451 http://dsbl.org/listing?221.161.131.55
Mar  4 11:14:29 icapws sendmail[11718]: k2293Unn003174: to=<dharvey@amfam.com>, delay=1+17:10:52, xdelay=00:00:01, mailer=esmtp, pri=3480380, relay=mr.glbext.amfam.com. [204.29.134.135], dsn=4.0.0, stat=Deferred
Mar  4 11:14:29 icapws sendmail[11718]: k2295Snn003180: to=<dmckee@adelphia.net>, delay=1+17:08:58, xdelay=00:00:00, mailer=esmtp, pri=3480380, relay=mx.adelphia.net., dsn=4.0.0, stat=Deferred
Mar  4 11:14:30 icapws sendmail[11044]: k220mVnn002138: to=<stk811@optonline.net>, delay=2+01:25:56, xdelay=00:00:03, mailer=esmtp, pri=3630380, relay=mx1.optonline.net. [167.206.4.77], dsn=4.2.1, stat=Deferred: 452 4.2.1 Your host 221.161.131.55 has no DNS record . If you are using a firewall please configure DNS and try again authoritative host not found: stk811@optonline.net
Mar  4 11:14:36 icapws sendmail[11044]: k220tQnn002163: to=<tym@worldnet.att.net>, delay=2+01:19:08, xdelay=00:00:05, mailer=esmtp, pri=3630380, relay=gateway1.worldnet.att.net. [204.127.134.23], dsn=4.0.0, stat=Deferred: 450 busy - please try later
Mar  4 11:14:36 icapws sendmail[11044]: k220tQnn002163: to=<ty67pat@adelphia.net>, delay=2+01:19:08, xdelay=00:00:00, mailer=esmtp, pri=3630380, relay=mx.adelphia.net., dsn=4.0.0, stat=Deferred
Mar  4 11:14:36 icapws sendmail[11044]: k220tQnn002163: to=<ty@shop.internet.net>, delay=2+01:19:08, xdelay=00:00:00, mailer=esmtp, pri=3630380, relay=shop.internet.net. [206.207.85.33], dsn=4.0.0, stat=Deferred: Connection refused by shop.internet.net.

tail 명령어를 이용한 최근 maillog입니다.

어떤 부분을 보아야하는지 알려주시면 감사하겠습니다.

좋은 주말 되세요.^^