I haven't received email.
[root@nagiosserver objects]# service postfix status
master (pid 2081) is running...
[root@nagiosserver objects]# tail -40 /var/log/maillog
Feb 17 08:19:49 nagiosserver sendmail[12090]: 01H8Jniv012090: from=root, size=219, class=0, nrcpts=1, msgid=<202002170819.01H8Jniv012090@nagiosserver>, relay=root@localhost
Feb 17 08:19:49 nagiosserver postfix/smtpd[11809]: connect from localhost[127.0.0.1]
Feb 17 08:19:49 nagiosserver postfix/smtpd[11809]: 9395328E2: client=localhost[127.0.0.1]
Feb 17 08:19:49 nagiosserver postfix/cleanup[11812]: 9395328E2: message-id=<202002170819.01H8Jniv012090@nagiosserver>
Feb 17 08:19:49 nagiosserver postfix/qmgr[2094]: 9395328E2: from=<
root@nagiosserver.localdomain>, size=665, nrcpt=1 (queue active)
Feb 17 08:19:49 nagiosserver sendmail[12090]: 01H8Jniv012090: to=
dheerushops@gmail.com, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30219, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (Ok: queued as 9395328E2)
Feb 17 08:19:49 nagiosserver postfix/error[11813]: 9395328E2: to=<
dheerushops@gmail.com>, relay=none, delay=0.05, delays=0.04/0/0/0, dsn=4.3.5, status=deferred (delivery temporarily suspended: Host or domain name not found. Name service error for name=smtp.example.com type=AAAA: Host not found)
Feb 17 08:19:49 nagiosserver postfix/smtpd[11809]: disconnect from localhost[127.0.0.1]
Feb 17 08:20:26 nagiosserver sendmail[12146]: 01H8KQaC012146: from=nagios, size=490, class=0, nrcpts=1, msgid=<202002170820.01H8KQaC012146@nagiosserver>, relay=nagios@localhost
Feb 17 08:20:26 nagiosserver postfix/smtpd[11809]: connect from localhost[127.0.0.1]
Feb 17 08:20:26 nagiosserver postfix/smtpd[11809]: 6FC753A67: client=localhost[127.0.0.1]
Feb 17 08:20:26 nagiosserver postfix/cleanup[11812]: 6FC753A67: message-id=<202002170820.01H8KQaC012146@nagiosserver>
Feb 17 08:20:26 nagiosserver postfix/qmgr[2094]: 6FC753A67: from=<
nagios@nagiosserver.localdomain>, size=946, nrcpt=1 (queue active)
Feb 17 08:20:26 nagiosserver sendmail[12146]: 01H8KQaC012146: to=
dheerushops@gmail.com, ctladdr=nagios (532/537), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30490, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (Ok: queued as 6FC753A67)
Feb 17 08:20:26 nagiosserver postfix/error[12052]: 6FC753A67: to=<
dheerushops@gmail.com>, relay=none, delay=0.05, delays=0.04/0/0/0, dsn=4.3.5, status=deferred (delivery temporarily suspended: Host or domain name not found. Name service error for name=smtp.example.com type=AAAA: Host not found)
Feb 17 08:20:26 nagiosserver postfix/smtpd[11809]: disconnect from localhost[127.0.0.1]
Feb 17 08:21:02 nagiosserver sendmail[12193]: 01H8L20V012193: from=root, size=219, class=0, nrcpts=1, msgid=<202002170821.01H8L20V012193@nagiosserver>, relay=root@localhost
Feb 17 08:21:02 nagiosserver postfix/smtpd[11809]: connect from localhost[127.0.0.1]
Feb 17 08:21:02 nagiosserver postfix/smtpd[11809]: C0B993A68: client=localhost[127.0.0.1]
Feb 17 08:21:02 nagiosserver postfix/cleanup[11812]: C0B993A68: message-id=<202002170821.01H8L20V012193@nagiosserver>
Feb 17 08:21:02 nagiosserver sendmail[12193]: 01H8L20V012193: to=
dheerushops@gmail.com, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30219, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (Ok: queued as C0B993A68)
Feb 17 08:21:02 nagiosserver postfix/qmgr[2094]: C0B993A68: from=<
root@nagiosserver.localdomain>, size=665, nrcpt=1 (queue active)
Feb 17 08:21:02 nagiosserver postfix/error[12059]: C0B993A68: to=<
dheerushops@gmail.com>, relay=none, delay=0.05, delays=0.05/0/0/0, dsn=4.3.5, status=deferred (delivery temporarily suspended: Host or domain name not found. Name service error for name=smtp.example.com type=AAAA: Host not found)
Feb 17 08:21:02 nagiosserver postfix/smtpd[11809]: disconnect from localhost[127.0.0.1]
Feb 17 08:21:49 nagiosserver sendmail[12255]: 01H8Lnqi012255: from=root, size=219, class=0, nrcpts=1, msgid=<202002170821.01H8Lnqi012255@nagiosserver>, relay=root@localhost
Feb 17 08:21:49 nagiosserver postfix/smtpd[11809]: connect from localhost[127.0.0.1]
Feb 17 08:21:49 nagiosserver postfix/smtpd[11809]: 665923A69: client=localhost[127.0.0.1]
Feb 17 08:21:49 nagiosserver postfix/cleanup[11812]: 665923A69: message-id=<202002170821.01H8Lnqi012255@nagiosserver>
Feb 17 08:21:49 nagiosserver postfix/qmgr[2094]: 665923A69: from=<
root@nagiosserver.localdomain>, size=665, nrcpt=1 (queue active)
Feb 17 08:21:49 nagiosserver sendmail[12255]: 01H8Lnqi012255: to=
dheerushops@gmail.com, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30219, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (Ok: queued as 665923A69)
Feb 17 08:21:49 nagiosserver postfix/error[12052]: 665923A69: to=<
dheerushops@gmail.com>, relay=none, delay=0.05, delays=0.04/0/0/0, dsn=4.3.5, status=deferred (delivery temporarily suspended: Host or domain name not found. Name service error for name=smtp.example.com type=AAAA: Host not found)
Feb 17 08:21:49 nagiosserver postfix/smtpd[11809]: disconnect from localhost[127.0.0.1]
[root@nagiosserver objects]#