Hi every one,
Recently I found there are lots incomming mail queues frozen in my cPanel exim server, after checking, I am sure this is because of cPanel wrong design.
Basically, the incomming mail queue frozen due to the Return-Failed(bounceback) messages drop by ACL, when the Return-Failed messages drop by ACL, it will cause incomming mail queue into "Process failed" state, and then frozen the incomming mail queue forever. For example, one of incomming mail send from invalid sender email address, it failed to delivery due to "LMTP error after MAIL FROM", and created a Return-Failed messages, but the Return-Failed messages also failed due to ACL drop it, then the incomming mail queue into "Porcess failed" state and then frozen forever.
Only when the Return-Failed message drop by ACL can cause this issue, if Return-Failed message sent successfully, or even rejected by remote SMTP server immediately, it will not cause this issue. The important thing is: the incomming mail queue will frozen forever, as it have not chance to delivery in this situtation. And I suspect it is the main reason why there are lots of old mail queue files under path /var/spool/exim/ when my cPanel exim server running for a while.
2019-10-22 00:10:33 1iMaGL-00GbWj-Jh <= Yourhealth–[email protected] H=(..) [x.x.x.x]:36502 P=esmtp S=11255 id=.. T=".." for ***@*****.com
2019-10-22 00:10:33 cwd=/var/spool/exim 3 args: /usr/sbin/exim -Mc 1iMaGL-00GbWj-Jh
2019-10-22 00:10:33 1iMaGL-00GbWj-Jh ** ***@*****.com R=virtual_user T=dovecot_virtual_delivery: LMTP error after MAIL FROM:<Yourhealth\342\200\[email protected]>: 500 5.5.2 Invalid command syntax
2019-10-22 00:10:33 cwd=/var/spool/exim 7 args: /usr/sbin/exim -t -oem -oi -f <> -E1iMaGL-00GbWj-Jh
2019-10-22 00:10:35 1iMaGP-00GbWx-Dz F=<> rejected by non-SMTP ACL: "SpamAssassin as cpaneleximscanner detected OUTGOING not smtp message as spam (7.9/70)"
2019-10-22 00:10:35 1iMaGP-00GbWx-Dz Error while reading message with no usable sender address (R=1iMaGL-00GbWj-Jh): rejected by non-SMTP ACL: This message was classified as SPAM and may not be delivered
2019-10-22 00:10:35 1iMaGL-00GbWj-Jh Process failed (1) when writing error message to Yourhealth–[email protected] (frozen)
2019-10-22 00:14:53 1iMaGL-00GbWj-Jh Message is frozen
Recently I found there are lots incomming mail queues frozen in my cPanel exim server, after checking, I am sure this is because of cPanel wrong design.
Basically, the incomming mail queue frozen due to the Return-Failed(bounceback) messages drop by ACL, when the Return-Failed messages drop by ACL, it will cause incomming mail queue into "Process failed" state, and then frozen the incomming mail queue forever. For example, one of incomming mail send from invalid sender email address, it failed to delivery due to "LMTP error after MAIL FROM", and created a Return-Failed messages, but the Return-Failed messages also failed due to ACL drop it, then the incomming mail queue into "Porcess failed" state and then frozen forever.
Only when the Return-Failed message drop by ACL can cause this issue, if Return-Failed message sent successfully, or even rejected by remote SMTP server immediately, it will not cause this issue. The important thing is: the incomming mail queue will frozen forever, as it have not chance to delivery in this situtation. And I suspect it is the main reason why there are lots of old mail queue files under path /var/spool/exim/ when my cPanel exim server running for a while.
2019-10-22 00:10:33 1iMaGL-00GbWj-Jh <= Yourhealth–[email protected] H=(..) [x.x.x.x]:36502 P=esmtp S=11255 id=.. T=".." for ***@*****.com
2019-10-22 00:10:33 cwd=/var/spool/exim 3 args: /usr/sbin/exim -Mc 1iMaGL-00GbWj-Jh
2019-10-22 00:10:33 1iMaGL-00GbWj-Jh ** ***@*****.com R=virtual_user T=dovecot_virtual_delivery: LMTP error after MAIL FROM:<Yourhealth\342\200\[email protected]>: 500 5.5.2 Invalid command syntax
2019-10-22 00:10:33 cwd=/var/spool/exim 7 args: /usr/sbin/exim -t -oem -oi -f <> -E1iMaGL-00GbWj-Jh
2019-10-22 00:10:35 1iMaGP-00GbWx-Dz F=<> rejected by non-SMTP ACL: "SpamAssassin as cpaneleximscanner detected OUTGOING not smtp message as spam (7.9/70)"
2019-10-22 00:10:35 1iMaGP-00GbWx-Dz Error while reading message with no usable sender address (R=1iMaGL-00GbWj-Jh): rejected by non-SMTP ACL: This message was classified as SPAM and may not be delivered
2019-10-22 00:10:35 1iMaGL-00GbWj-Jh Process failed (1) when writing error message to Yourhealth–[email protected] (frozen)
2019-10-22 00:14:53 1iMaGL-00GbWj-Jh Message is frozen
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