A customer sent 6 test messages in a space of about 30 minutes. 5 out of 6 never appeared in the maillogs of 3 different relays I am still trying to get more detail from them.
The one that did go through showed, IMHO, strange behavior: 2022-08-05T17:27:37.326857+00:00 MAILRELAY postfix/smtpd[69606]: connect from unknown[SAME_CLIENT_IP] 2022-08-05T17:28:05.229942+00:00 MAILRELAY postfix/smtpd[69634]: connect from unknown[SAME_CLIENT_IP] 2022-08-05T17:31:50.711513+00:00 MAILRELAY postfix/smtpd[69638]: connect from unknown[SAME_CLIENT_IP] 2022-08-05T17:32:43.057669+00:00 MAILRELAY postfix/smtpd[69606]: timeout after CONNECT from unknown[SAME_CLIENT_IP] 2022-08-05T17:32:43.058413+00:00 MAILRELAY postfix/smtpd[69606]: disconnect from unknown[SAME_CLIENT_IP] commands=0/0 2022-08-05T17:33:16.299108+00:00 MAILRELAY postfix/smtpd[69634]: timeout after UNKNOWN from unknown[SAME_CLIENT_IP] 2022-08-05T17:33:16.299730+00:00 MAILRELAY postfix/smtpd[69634]: disconnect from unknown[SAME_CLIENT_IP] unknown=0/2 commands=0/2 Three connections from the same source, two timed out quickly 2022-08-05T17:36:43.530386+00:00 MAILRELAY postfix/smtpd[69667]: connect from unknown[SAME_CLIENT_IP] A 4th connections from the same source, this one actually performed as expected 2022-08-05T17:36:43.557118+00:00 MAILRELAY postfix/smtpd[69667]: discarding EHLO keywords: CHUNKING 2022-08-05T17:36:43.584122+00:00 MAILRELAY postfix/smtpd[69667]: 8E90F800298: client=unknown[SAME_CLIENT_IP] 2022-08-05T17:36:43.611390+00:00 MAILRELAY postfix/cleanup[69670]: 8E90F800298: message-id=<20220805173643.58CA11A2F14@sendinghost.local> 2022-08-05T17:36:43.621314+00:00 MAILRELAY spamd[48573]: spamd: connection from 127.0.0.1 [127.0.0.1]:53528 to port 783, fd 5 2022-08-05T17:36:43.624192+00:00 MAILRELAY spamd[48573]: spamd: setuid to sa-milt succeeded 2022-08-05T17:36:43.627832+00:00 MAILRELAY spamd[48573]: spamd: processing message <20220805173643.58CA11A2F14@sendinghost.local> for sa-milt:989 2022-08-05T17:36:43.877290+00:00 MAILRELAY spamd[48573]: spamd: clean message (1.8/5.0) for sa-milt:989 in 0.3 seconds, 761 bytes. 2022-08-05T17:36:43.877489+00:00 MAILRELAY spamd[48573]: spamd: result: . 1 - RCVD_IN_DNSWL_BLOCKED,RDNS_NONE,SPF_HELO_NONE,SPF_PASS,SUBJ_ALL_CAPS scantime=0.3,size=761,user=sa-milt,uid=989,required_score=5.0,rhost=127.0.0.1,raddr=127.0.0.1,rport=53528,mid=<20220805173643.58CA11A2F14@sendinghost.local>,autolearn=no autolearn_force=no 2022-08-05T17:36:43.893896+00:00 MAILRELAY postfix/qmgr[69362]: 8E90F800298: from=<SENDER>, size=647, nrcpt=2 (queue active) 2022-08-05T17:36:43.894495+00:00 MAILRELAY postfix/smtpd[69667]: disconnect from unknown[SAME_CLIENT_IP] ehlo=1 mail=1 rcpt=2 data=1 quit=1 commands=6 2022-08-05T17:36:43.902779+00:00 MAILRELAY spamd[48495]: prefork: child states: II 2022-08-05T17:36:44.308292+00:00 MAILRELAY postfix/smtp[69672]: 8E90F800298: to=<DESTINATION1>, relay=UPSTREAM_RELAY[UPSTREAM_RELAY]:25, delay=0.73, delays=0.31/0/0.19/0.23, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as 16ECF8015D6) 2022-08-05T17:36:44.308778+00:00 MAILRELAY postfix/smtp[69672]: 8E90F800298: to=<DESTINATION2>, relay=UPSTREAM_RELAY[UPSTREAM_RELAY]:25, delay=0.73, delays=0.31/0/0.19/0.23, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as 16ECF8015D6) 2022-08-05T17:36:44.308860+00:00 MAILRELAY postfix/qmgr[69362]: 8E90F800298: removed And the final connection timed out 2022-08-05T17:36:53.703951+00:00 MAILRELAY postfix/smtpd[69638]: timeout after CONNECT from unknown[SAME_CLIENT_IP] 2022-08-05T17:36:53.704553+00:00 MAILRELAY postfix/smtpd[69638]: disconnect from unknown[SAME_CLIENT_IP] commands=0/0 Can anyone shed any light on this head-scratcher ? ______________________________________________________________________________________________ Daniel E. White daniel.e.wh...@nasa.gov<mailto:daniel.e.wh...@nasa.gov> NASCOM Linux Engineer NASA Goddard Space Flight Center Office: (301) 286-6919 Mobile: (240) 513-5290