Ca marche pas.
Voici les logs, 10.0.0.10 étant le serveur DNS et 10.0.0.12 étant le serveur postfix
Sep 1 19:13:22 serveurmail postfix/qmgr[13787]: AE0DC46E94: from=<root@ensias.org>, size=322, nrcpt=1 (queue active)
Sep 1 19:13:22 serveurmail postfix/smtp[13863]: connect to ensias.org[10.0.0.10]:25: Connection refused
Sep 1 19:13:22 serveurmail postfix/smtp[13863]: AE0DC46E94: to=<root@ensias.org>, relay=none, delay=1153, delays=1153/0.03/0.01/0, dsn=4.4.1, status=deferred (connect to ensias.org[10.0.0.10]:25: Connection refused)
Sep 1 19:18:22 serveurmail postfix/qmgr[13787]: C0F9046EA8: from=<root@ensias.org>, size=332, nrcpt=1 (queue active)
Sep 1 19:18:22 serveurmail postfix/smtp[13872]: connect to ensias.org[10.0.0.10]:25: Connection refused
Sep 1 19:18:22 serveurmail postfix/smtp[13872]: C0F9046EA8: to=<root@ensias.org>, relay=none, delay=941, delays=941/0.02/0.01/0, dsn=4.4.1, status=deferred (connect to ensias.org[10.0.0.10]:25: Connection refused)
Sep 1 19:33:22 serveurmail postfix/qmgr[13787]: AE0DC46E94: from=<root@ensias.org>, size=322, nrcpt=1 (queue active)
Sep 1 19:33:22 serveurmail postfix/smtp[13886]: connect to ensias.org[10.0.0.10]:25: Connection refused
Sep 1 19:33:22 serveurmail postfix/smtp[13886]: AE0DC46E94: to=<root@ensias.org>, relay=none, delay=2353, delays=2353/0.02/0/0, dsn=4.4.1, status=deferred (connect to ensias.org[10.0.0.10]:25: Connection refused)
Sep 1 19:36:35 serveurmail postfix/smtpd[13890]: connect from unknown[10.0.0.12]
Sep 1 19:37:24 serveurmail postfix/smtpd[13890]: 3F2DF46EAA: client=unknown[10.0.0.12]
Sep 1 19:37:30 serveurmail postfix/cleanup[13894]: 3F2DF46EAA: message-id=<20130901183724.3F2DF46EAA@serveurmail.ensias.org>
Sep 1 19:37:30 serveurmail postfix/qmgr[13787]: 3F2DF46EAA: from=<root@ensias.org>, size=318, nrcpt=1 (queue active)
Sep 1 19:37:30 serveurmail postfix/smtp[13895]: connect to ensias.org[10.0.0.10]:25: Connection refused
Sep 1 19:37:30 serveurmail postfix/smtp[13895]: 3F2DF46EAA: to=<root@ensias.org>, relay=none, delay=21, delays=21/0.01/0/0, dsn=4.4.1, status=deferred (connect to ensias.org[10.0.0.10]:25: Connection refused)
Sep 1 19:37:43 serveurmail postfix/smtpd[13890]: disconnect from unknown[10.0.0.12]
Sep 1 19:37:53 serveurmail postfix/smtpd[13890]: connect from unknown[10.0.0.12]
Sep 1 19:38:13 serveurmail postfix/smtpd[13890]: disconnect from unknown[10.0.0.12]
Sep 1 19:38:22 serveurmail postfix/qmgr[13787]: C0F9046EA8: from=<root@ensias.org>, size=332, nrcpt=1 (queue active)
Sep 1 19:38:22 serveurmail postfix/smtp[13895]: connect to ensias.org[10.0.0.10]:25: Connection refused
Sep 1 19:38:22 serveurmail postfix/smtp[13895]: C0F9046EA8: to=<root@ensias.org>, relay=none, delay=2141, delays=2141/0/0.01/0, dsn=4.4.1, status=deferred (connect to ensias.org[10.0.0.10]:25: Connection refused)
Sep 1 19:41:34 serveurmail postfix/anvil[13892]: statistics: max connection rate 1/60s for (smtp:10.0.0.12) at Sep 1 19:36:35
Sep 1 19:41:34 serveurmail postfix/anvil[13892]: statistics: max connection count 1 for (smtp:10.0.0.12) at Sep 1 19:36:35
Sep 1 19:41:34 serveurmail postfix/anvil[13892]: statistics: max cache size 1 at Sep 1 19:36:35
Sep 1 19:42:43 serveurmail postfix/smtpd[13911]: connect from unknown[10.0.0.12]
Sep 1 19:43:05 serveurmail postfix/smtpd[13911]: disconnect from unknown[10.0.0.12]
Sep 1 19:43:07 serveurmail postfix/smtpd[13911]: connect from unknown[10.0.0.12]
Sep 1 19:43:22 serveurmail postfix/qmgr[13787]: 3F2DF46EAA: from=<root@ensias.org>, size=318, nrcpt=1 (queue active)
Sep 1 19:43:22 serveurmail postfix/smtp[13916]: connect to ensias.org[10.0.0.10]:25: Connection refused
Sep 1 19:43:22 serveurmail postfix/smtp[13916]: 3F2DF46EAA: to=<root@ensias.org>, relay=none, delay=373, delays=373/0.02/0/0, dsn=4.4.1, status=deferred (connect to ensias.org[10.0.0.10]:25: Connection refused)
Sep 1 19:43:23 serveurmail postfix/smtpd[13911]: disconnect from unknown[10.0.0.12]
Sep 1 19:43:26 serveurmail postfix/smtpd[13911]: connect from unknown[10.0.0.12]
Sep 1 19:43:54 serveurmail postfix/smtpd[13911]: 77C1E46EB0: client=unknown[10.0.0.12]
Sep 1 19:44:06 serveurmail postfix/cleanup[13921]: 77C1E46EB0: message-id=<20130901184354.77C1E46EB0@serveurmail.ensias.org>
Sep 1 19:44:06 serveurmail postfix/qmgr[13787]: 77C1E46EB0: from=<root@ensias.org>, size=323, nrcpt=1 (queue active)
Sep 1 19:44:06 serveurmail postfix/smtp[13916]: connect to ensias.org[10.0.0.10]:25: Connection refused
Sep 1 19:44:06 serveurmail postfix/smtp[13916]: 77C1E46EB0: to=<root@ensias.org>, relay=none, delay=30, delays=30/0/0/0, dsn=4.4.1, status=deferred (connect to ensias.org[10.0.0.10]:25: Connection refused)
Sep 1 19:44:09 serveurmail postfix/smtpd[13911]: disconnect from unknown[10.0.0.12]
Sep 1 19:44:13 serveurmail postfix/smtpd[13911]: connect from unknown[10.0.0.12]
Sep 1 19:44:25 serveurmail postfix/smtpd[13911]: disconnect from unknown[10.0.0.12]
J’ai autorisé le traffic tcp et udp entrant sur le port 25 du serveur DNS mais ça change rien.