While testing email from AM we're using an non-existent envelope-from now:
2020-11-30 13:07:43 1kjiu7-0005N8-J1 <= alertmanager@wikimedia.org H=(localhost) [::1]:55726 I=[::1]:25 P=esmtp S=10584 id=1606741663590089237.16654494479565861601@alert1001 2020-11-30 13:07:43 1kjiu7-0005N8-J1 ** ayounsi@wikimedia.org R=smart_route T=remote_smtp H=mx1001.wikimedia.org [2620:0:861:3:208:80:154:76] I=[2620:0:861:3:208:80:154:88]: SMTP error from remote mail server after RCPT TO:<ayounsi@wikimedia.org>: 550-Verification failed for <alertmanager@wikimedia.org>\n550-Address alertmanager@wikimedia.org does not exist\n550 Sender verify failed 2020-11-30 13:07:43 1kjiu7-0005Nj-LM <= <> R=1kjiu7-0005N8-J1 U=Debian-exim P=local S=12310 2020-11-30 13:07:43 1kjiu7-0005N8-J1 Completed 2020-11-30 13:07:43 1kjiu7-0005Nj-LM ** alertmanager@wikimedia.org R=smart_route T=remote_smtp H=mx1001.wikimedia.org[2620:0:861:3:208:80:154:76] I=[2620:0:861:3:208:80:154:88]: SMTP error from remote mail server after RCPT TO:<alertmanager@wikimedia.org>: 550 Address alertmanager@wikimedia.org does not exist 2020-11-30 13:07:43 1kjiu7-0005Nj-LM alertmanager@wikimedia.org: error ignored 2020-11-30 13:07:43 1kjiu7-0005Nj-LM Completed