안녕하세요 저는 로컬 프로그램에서 기본 메일 서버로 메일을 릴레이하기 위해 Centos 7 서버에 sendmail을 설정하려고 합니다. 저는 sendmail.mc를 다음과 같이 구성했습니다. mail.[domain].com은 SMTP 서버입니다.
정의('SMART_HOST', 'mail.[도메인].com')dnl
그리고
기능(
nullclient',mail.[도메인].com') dnl
다음은 이 메일을 보내려고 시도한 sendmail 로그입니다.
Aug 24 11:52:18 centos7 sendmail[21975]: w7O8qIUJ021975: Authentication-Warning: centos7.[domain]: openproject set sender to info@[domain].com using -f
Aug 24 11:52:18 centos7 sendmail[21975]: w7O8qIUJ021975: from=info@[domain].com, size=2587, class=-60, nrcpts=1, msgid=<5b7fc7423c037_218b2acdfb6fcf7c2088c@centos7.[domain].mail>, relay=openproject@localhost
Aug 24 11:52:18 centos7 sendmail[21976]: w7O8qIMw021976: from=<info@[domain].com>, size=2854, class=-60, nrcpts=1, msgid=<5b7fc7423c037_218b2acdfb6fcf7c2088c@centos7.[domain].mail>, proto=ESMTP, daemon=MTA, relay=localhost [127.0.0.1]
Aug 24 11:52:18 centos7 sendmail[21975]: w7O8qIUJ021975: to=dennis@[domain].com, ctladdr=info@[domain].com (988/982), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=140587, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (w7O8qIMw021976 Message accepted for delivery)
Aug 24 11:52:18 centos7 sendmail[21978]: STARTTLS=client, relay=mail.[domain].com., version=TLSv1/SSLv3, verify=FAIL, cipher=ECDHE-RSA-AES256-SHA384, bits=256/256
Aug 24 11:52:18 centos7 sendmail[21978]: w7O8qIMw021976: to=<dennis@[domain].com>, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=230854, relay=mail.[domain].com. [192.168.111.10], dsn=5.1.1, stat=User unknown
Aug 24 11:52:18 centos7 sendmail[21978]: w7O8qIMw021976: w7O8qIMw021978: DSN: User unknown
Aug 24 11:52:18 centos7 sendmail[21978]: w7O8qIMw021978: to=<info@[domain].com>, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30000, relay=mail.[domain].com. [192.168.111.10], dsn=5.1.1, stat=User unknown
Aug 24 11:52:18 centos7 sendmail[21978]: w7O8qIMw021978: w7O8qIMx021978: return to sender: User unknown
Aug 24 11:52:18 centos7 sendmail[21978]: w7O8qIMx021978: to=postmaster, delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30000, relay=mail.[domain].com. [192.168.111.10], dsn=5.1.1, stat=User unknown
Aug 24 11:52:18 centos7 sendmail[21978]: w7O8qIMw021978: Losing ./qfw7O8qIMw021978: savemail panic
Aug 24 11:52:18 centos7 sendmail[21978]: w7O8qIMw021978: SYSERR(root): savemail: cannot save rejected email anywhere
이제 sendmail 로그에 따르면 내 이메일 dennis@[domain].com이 존재하지 않는 것처럼 보이는데, 존재하기 때문에 이상합니다. 하지만 메일 서버의 로그를 보면 약간 다른 내용이 나와 있습니다.
Fri 2018-08-24 11:52:18.667: Session 471387; child 0001
Fri 2018-08-24 11:52:18.667: Accepting SMTP connection from 192.168.111.15:42300 to 192.168.111.10:25
Fri 2018-08-24 11:52:18.670: --> 220 xxxx ESMTP MDaemon 18.0.2; Fri, 24 Aug 2018 11:52:18 +0300
Fri 2018-08-24 11:52:18.672: <-- EHLO centos7.[domain]
Fri 2018-08-24 11:52:18.673: --> 250-xxxxx Hello centos7.[domain] [192.168.111.15], pleased to meet you
Fri 2018-08-24 11:52:18.673: --> 250-ETRN
Fri 2018-08-24 11:52:18.673: --> 250-AUTH LOGIN CRAM-MD5 PLAIN
Fri 2018-08-24 11:52:18.673: --> 250-8BITMIME
Fri 2018-08-24 11:52:18.674: --> 250-ENHANCEDSTATUSCODES
Fri 2018-08-24 11:52:18.674: --> 250-STARTTLS
Fri 2018-08-24 11:52:18.674: --> 250 SIZE
Fri 2018-08-24 11:52:18.683: <-- STARTTLS
Fri 2018-08-24 11:52:18.683: --> 220 2.7.0 Ready to start TLS
Fri 2018-08-24 11:52:18.705: SSL negotiation successful (TLS 1.2, 256 bit key exchange, 256 bit AES encryption)
Fri 2018-08-24 11:52:18.716: <-- EHLO centos7.[domain]
Fri 2018-08-24 11:52:18.716: --> 250-xxxxx Hello centos7.[domain] [192.168.111.15], pleased to meet you
Fri 2018-08-24 11:52:18.716: --> 250-ETRN
Fri 2018-08-24 11:52:18.716: --> 250-AUTH LOGIN CRAM-MD5 PLAIN
Fri 2018-08-24 11:52:18.716: --> 250-8BITMIME
Fri 2018-08-24 11:52:18.716: --> 250-ENHANCEDSTATUSCODES
Fri 2018-08-24 11:52:18.716: --> 250 SIZE
Fri 2018-08-24 11:52:18.724: <-- MAIL From:<info@mail.[domain].com> SIZE=3046
Fri 2018-08-24 11:52:18.726: --> 250 2.1.0 Sender OK
Fri 2018-08-24 11:52:18.754: <-- RCPT To:<dennis@mail.[domain].com>
Fri 2018-08-24 11:52:18.755: Sender attempted to deliver message to unknown address
따라서 어떤 이유로 보낸 사람과 받는 사람 이메일 주소의 도메인 부분이 손상되었습니다. 실제로는 dennis@[domain].com으로 보내려고 하는데 메일 서버는 누군가 dennis@mail.[domain].com으로 보내려고 한다고 생각합니다.
왜 이런 일이 일어나는지 모르겠습니다.
답변1
흠, 거의 당황스러울 정도지만 계속해서 sendmail.mc 파일을 살펴보고 이전에 활성화한 다음 비트를 발견하고 LOCAL_DOMAIN 줄에 주석을 달자 모든 것이 작동하기 시작했습니다.
dnl # Also accept email sent to "localhost.localdomain" as local email.
dnl #
LOCAL_DOMAIN(`[domain].com')dnl