Apr 17 12:13:13 pmg2 postfix/smtpd[1922082]: 30CB6181CA4: client=localhost.localdomain[127.0.0.1], orig_client=my.plesk.server[1.2.3.4]
Apr 17 12:13:13 pmg2 postfix/cleanup[1922083]: 30CB6181CA4: message-id=<aec06bdd8c34e4d495b31ae96cbf645a@sendingdomain.com>
Apr 17 12:13:13 pmg2 postfix/qmgr[1056165]: 30CB6181CA4: from=<info@sendingdomain.com>, size=6556, nrcpt=1 (queue active)
Apr 17 12:13:13 pmg2 pmg-smtp-filter[1919705]: 181CA3643D29C89082C: accept mail to <receiver@receiverdomain.com> (30CB6181CA4) (rule: default-accept)
Apr 17 12:13:16 pmg2 postfix/smtp[1922084]: 30CB6181CA4: host extmail.receiverdomain.com[25.6.7.8] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command)
Apr 17 12:13:20 pmg2 postfix/smtp[1922084]: 30CB6181CA4: to=<receiver@receiverdomain.com>, relay=extmail.receiverdomain.com[x.x.x.x]:25, delay=7.4, delays=0.05/0/7/0.31, dsn=4.0.0, status=deferred (host extmail.receiverdomain.com[203.36.172.106] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command))
Apr 17 12:22:48 pmg2 postfix/qmgr[1056165]: 30CB6181CA4: from=<info@sendingdomain.com>, size=6556, nrcpt=1 (queue active)
Apr 17 12:22:52 pmg2 postfix/smtp[1924051]: 30CB6181CA4: host extmail.receiverdomain.com[203.36.172.106] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command)
Apr 17 12:22:55 pmg2 postfix/smtp[1924051]: 30CB6181CA4: to=<receiver@receiverdomain.com>, relay=extmail.receiverdomain.com[x.x.x.x]:25, delay=582, delays=576/0.08/6.2/0.29, dsn=4.0.0, status=deferred (host extmail.receiverdomain.com[25.6.7.8] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command))
Apr 17 12:32:49 pmg2 postfix/qmgr[1056165]: 30CB6181CA4: from=<info@sendingdomain.com>, size=6556, nrcpt=1 (queue active)
Apr 17 12:32:51 pmg2 postfix/smtp[1925997]: 30CB6181CA4: host extmail.receiverdomain.com[203.36.172.106] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command)
Apr 17 12:32:54 pmg2 postfix/smtp[1925997]: 30CB6181CA4: to=<receiver@receiverdomain.com>, relay=extmail.receiverdomain.com[x.x.x.x]:25, delay=1181, delays=1176/0.06/5/0.29, dsn=4.0.0, status=deferred (host extmail.receiverdomain.com[25.6.7.8] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command))
Apr 17 12:52:49 pmg2 postfix/qmgr[1056165]: 30CB6181CA4: from=<info@sendingdomain.com>, size=6556, nrcpt=1 (queue active)
Apr 17 12:52:52 pmg2 postfix/smtp[1930078]: 30CB6181CA4: host extmail.receiverdomain.com[25.6.7.8] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command)
Apr 17 12:52:55 pmg2 postfix/smtp[1930078]: 30CB6181CA4: to=<receiver@receiverdomain.com>, relay=extmail.receiverdomain.com[x.x.x.x]:25, delay=2382, delays=2376/0.11/5.4/0.31, dsn=4.0.0, status=deferred (host extmail.receiverdomain.com[203.36.172.106] said: 451 <info@sendingdomain.com> unable to verify address (in reply to MAIL FROM command))