메일서버 관련 내용입니다.

안녕하세요. 다름이 아니고 mail 함수를 이용해서 웹매거진 형식의 메일들을 발송을 했었습니다. 그런데 오늘 보니까
메일이 안갑니다. 몇일전에 서버를 재부팅한적이 있었긴 하지만 예전에도 자주는 아니지만 가끔식 재부팅을 했었는데
그때는 이상이 없었던것 같습니다. 현재 네임서버+웹서버+DB서버 이렇게 구성되어 있고 메일서버는 네임서버에 설치
되어 있습니다. 하지만 위의 웹매거진 메일은 웹서버에서 php함수인 mail 함수를 사용해서 날렸었습니다. 전에는 이상
없이 되었습니다. 현재 회사 메일로는 메일발송이 되었었습니다. 그리고 네이버 메일은 발송이 되었습니다. 그런데
hanmail.net , lycos.co.kr 메일은 발송이 안됩니다. 예전에 lycos.co.kr 메일로 확인을 했었는데 이상이 없었는데
오늘은 안됩니다. 아래는 메일 로그 입니다.

사용한 계정은 abcd@hanmail.net,abcd@lycos.co.kr,abcd@naver.com 과 회사메일 abcd@woori.co.kr 입니다.
(그냥 예를 들어놓은 이메일들입니다. 실제 이메일 계정은 틀립니다. ㅡ.,ㅡ)

발송안되었던 메일 로그 ####################
Jun 23 10:30:43 localhost sendmail[10401]: k5N1UhvW010401: from=apache, size=111, class=0, nrcpts=1, msgid=<200606230130.k5N1UhvW010401@localhost.localdomain>, relay=apache@localhost
Jun 23 10:30:43 localhost sendmail[10403]: k5N1UhZI010403: from=, size=347, class=0, nrcpts=1, msgid=<200606230130.k5N1UhvW010401@localhost.localdomain>, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1]
Jun 23 10:30:43 localhost sendmail[10401]: k5N1UhvW010401: to=abcd@lycos.co.kr, ctladdr=apache (48/48), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30105, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (k5N1UhZI010403 Message accepted for delivery)
Jun 23 10:30:43 localhost sendmail[10405]: k5N1UhZI010403: to=, ctladdr= (48/48), delay=00:00:00, xdelay=00:00:00, mailer=esmtp, pri=30341, relay=kr-inmail.lycos.co.kr. [203.226.255.61], dsn=4.0.0, stat=Deferred: 421 4.5.4 EHLO domain is invalid.

Jun 23 10:31:43 localhost sendmail[10411]: k5N1VhK7010411: to=abcd@hanmail.net, ctladdr=apache (48/48), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30105, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (k5N1VhZI010413 Message accepted for delivery)
Jun 23 10:31:44 localhost sendmail[10415]: k5N1VhZI010413: to=, ctladdr= (48/48), delay=00:00:01, xdelay=00:00:01, mailer=esmtp, pri=30341, relay=mx2.hanmail.net. [211.43.197.78], dsn=4.0.0, stat=Deferred: 441 4.4.1 temporay dns failed
Jun 23 10:32:03 localhost sendmail[10416]: k5N1W3Po010416: from=apache, size=111, class=0, nrcpts=1, msgid=<200606230132.k5N1W3Po010416@localhost.localdomain>, relay=apache@localhost
Jun 23 10:32:04 localhost sendmail[10418]: k5N1W3ZI010418: from=, size=347, class=0, nrcpts=1, msgid=<200606230132.k5N1W3Po010416@localhost.localdomain>, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1]

발송되었던 메일 로그 ####################
Jun 23 10:34:37 localhost sendmail[10423]: k5N1Yb7K010423: to=abcd@woori.co.kr, ctladdr=apache (48/48), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30103, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (k5N1YbZI010425 Message accepted for delivery)
Jun 23 10:34:37 localhost sendmail[10427]: k5N1YbZI010425: to=, ctladdr= (48/48), delay=00:00:00, xdelay=00:00:00, mailer=esmtp, pri=30339, relay=mail.ebit.co.kr. [222.122.148.104], dsn=2.0.0, stat=Sent (k5N1ggLa024475 Message accepted for delivery)
Jun 23 10:44:15 localhost sendmail[10438]: k5N1iDZI010438: from=, size=347, class=0, nrcpts=1, msgid=<200606230144.k5N1iDgV010436@localhost.localdomain>, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1]

Jun 23 10:31:20 localhost sendmail[10406]: k5N1VKdM010406: from=apache, size=109, class=0, nrcpts=1, msgid=<200606230131.k5N1VKdM010406@localhost.localdomain>, relay=apache@localhost
Jun 23 10:31:20 localhost sendmail[10408]: k5N1VKZI010408: from=, size=345, class=0, nrcpts=1, msgid=<200606230131.k5N1VKdM010406@localhost.localdomain>, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1]
Jun 23 10:31:20 localhost sendmail[10406]: k5N1VKdM010406: to=abcd@naver.com, ctladdr=apache (48/48), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30103, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (k5N1VKZI010408 Message accepted for delivery)
Jun 23 10:31:20 localhost sendmail[10410]: k5N1VKZI010408: to=, ctladdr= (48/48), delay=00:00:00, xdelay=00:00:00, mailer=esmtp, pri=30339, relay=rcvmail7.naver.com. [211.218.150.77], dsn=2.0.0, stat=Sent (2.5.0 Message accepted for delivery)

그런데 /var/spool/mqueue 에 파일들이 엄청 많이 있었습니다. 그래서 mqueue 디렉토리를 통채로 삭제하고 전에 대로 다시 생성해놨습니다.
생성한 mqueue 디렉토리는 아래와 같습니다. (예전 소유권과 모든것을 동일하게 생성했습니다)
drwx------ 2 root mail 4096 6월 23 10:50 mqueue
그런데 이 작업을 하고 난후 다시 메일을 발송했는데 아까 위에서 되었던 회사메일과 naver.com 메일로도 메일이 발송이 안됩니다.
관련 로그는 아래와 같습니다.

Jun 23 11:07:30 localhost sendmail[10466]: k5N27UGT010466: to=abcd@lycos.co.kr, ctladdr=apache (48/48), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30105, relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, stat=Deferred: 421 4.3.0 collect: Cannot write ./dfk5N27UZI010468 (bfcommit, uid=0, gid=51): No such file or directory
Jun 23 11:08:15 localhost sendmail[10473]: k5N28FJt010473: from=apache, size=5510, class=0, nrcpts=1, msgid=<200606230208.k5N28FJt010473@localhost.localdomain>, relay=apache@localhost
Jun 23 11:08:15 localhost sendmail[10475]: k5N28FZI010475: SYSERR(root): collect: Cannot write ./dfk5N28FZI010475 (sm_io_flush||sm_io_error, uid=0, gid=51): Input/output error
Jun 23 11:08:15 localhost sendmail[10475]: k5N28FZI010475: from=, size=5746, class=0, nrcpts=1, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1]
Jun 23 11:08:15 localhost sendmail[10473]: k5N28FJt010473: to=\377\377\377\377\377\377 , ctladdr=apache (48/48), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30138, relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, stat=Deferred: 421 4.3.0 collect: Cannot write ./dfk5N28FZI010475 (sm_io_flush||sm_io_error, uid=0, gid=51): Input/output error
Jun 23 11:09:43 localhost sendmail[10476]: k5N29hRh010476: from=apache, size=109, class=0, nrcpts=1, msgid=<200606230209.k5N29hRh010476@localhost.localdomain>, relay=apache@localhost
Jun 23 11:09:43 localhost sendmail[10478]: k5N29hZI010478: SYSERR(root): collect: Cannot write ./dfk5N29hZI010478 (bfcommit, uid=0, gid=51): No such file or directory
Jun 23 11:09:43 localhost sendmail[10478]: k5N29hZI010478: from=, size=345, class=0, nrcpts=1, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1]
Jun 23 11:09:43 localhost sendmail[10476]: k5N29hRh010476: to=abcd@naver.com, ctladdr=apache (48/48), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30103, relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, stat=Deferred: 421 4.3.0 collect: Cannot write ./dfk5N29hZI010478 (bfcommit, uid=0, gid=51): No such file or directory
Jun 23 11:26:59 localhost sendmail[10500]: k5N2QxZI010500: SYSERR(root): collect: Cannot write ./dfk5N2QxZI010500 (bfcommit, uid=0, gid=51): No such file or directory
Jun 23 11:26:59 localhost sendmail[10500]: k5N2QxZI010500: from=, size=345, class=0, nrcpts=1, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1]
Jun 23 11:26:59 localhost sendmail[10498]: k5N2Qui4010498: to=abcd@ebit.co.kr, ctladdr=apache (48/48), delay=00:00:03, xdelay=00:00:00, mailer=relay, pri=30103, relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, stat=Deferred: 421 4.3.0 collect: Cannot write ./dfk5N2QxZI010500 (bfcommit, uid=0, gid=51): No such file or directory

위에서 회사 메일은 위에 언급한대로 네임서버상에 붙어있는 메일서버를 사용하고 있어서 실제로 지금 메일이 발송이
안되는 웹서버와는 별개의 것입니다. 현재 위와 같은 상황입니다.
현재 상황이 php함수인 mail 함수를 사용해서 메일 발송이 안되는것이 문제 이거든요.
이럴때는 어떻게 해야 할까요? 조언 좀 부탁드립니다 (__)