Содержимое /var/maillog:
Sep 19 00:00:00 host newsyslog[61022]: logfile turned over
Sep 19 03:01:01 host sendmail[61492]: gethostbyaddr(10.10.10.10) failed: 1
Sep 19 03:01:02 host sendmail[61546]: gethostbyaddr(10.10.10.10) failed: 1
Sep 19 04:02:32 host sendmail[61868]: x8J12W7N061868: from=root, size=18686, class=0, nrcpts=1, msgid=<201909190102.x8J12W7N061868@host.network>, relay=root@localhost
Sep 19 04:02:32 host sendmail[61868]: x8J12W7N061868: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=48686, relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, stat=Deferred: Connection refused by [127.0.0.1]
Sep 19 04:02:32 host sendmail[61953]: x8J12W7N061868: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=138686, relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, stat=Deferred: Connection refused by [127.0.0.1]
Sep 19 04:02:32 host sendmail[61932]: gethostbyaddr(10.10.10.10) failed: 1
Sep 19 04:02:32 host sendmail[61932]: STARTTLS=client: file /etc/mail/certs/host.cert unsafe: No such file or directory
Sep 19 04:02:32 host sendmail[61932]: STARTTLS=client: file /etc/mail/certs/host.key unsafe: No such file or directory
Sep 19 04:02:32 host sendmail[61932]: STARTTLS=client: file /etc/mail/certs/cacert.pem unsafe: No such file or directory
Sep 19 04:02:32 host sendmail[61932]: STARTTLS=client, error: load verify locs /etc/mail/certs, /etc/mail/certs/cacert.pem failed: 0
Sep 19 04:02:36 host sendmail[61959]: x8J12aNn061959: from=root, size=2084, class=0, nrcpts=1, msgid=<201909190102.x8J12aNn061959@host.network>, relay=root@localhost
Sep 19 04:02:36 host sendmail[61959]: x8J12aNn061959: to=root, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=32084, relay=[127.0.0.1] [127.0.0.1], dsn=4.0.0, stat=Deferred: Connection refused by [127.0.0.1]
Подскажите, пожалуйста, что это может быть.