Question Where are mails to root stored and how to forward them to an external address?

[kassi]

Server operating system version

Ubuntu 22.04

Plesk version and microupdate number

18.0.58 #2

In the syslog I see mails being sent to root@myserver.mydomain e.g. from cron, which postfix manages the following:

Feb 18 13:33:02 myserver plesk-sendmail[41385]: S41385: from=<root@myserver.mydomain.tld> to=<root>
Feb 18 13:33:02 myserver plesk-sendmail[41386]: S41385: add-from: stderr: PASS
Feb 18 13:33:02 myserver plesk-sendmail[41386]: S41385: check-quota: stderr: SKIP
Feb 18 13:33:03 myserver postfix/pickup[32801]: 16AD01C0AED: uid=0 from=<root>
Feb 18 13:33:03 myserver postfix/cleanup[35855]: 16AD01C0AED: message-id=<20240218123303.16AD01C0AED@myserver.mydomain.tld>
Feb 18 13:33:03 myserver postfix/qmgr[14721]: 16AD01C0AED: from=<root@myserver.mydomain.tld>, size=1332, nrcpt=1 (queue active)
Feb 18 13:33:03 myserver postfix/cleanup[35392]: 174601C0AEC: message-id=<20240218123303.16AD01C0AED@myserver.mydomain.tld>
Feb 18 13:33:03 myserver postfix/local[33361]: 16AD01C0AED: to=<root@localhost.localdomain>, orig_to=<root>, relay=local, delay=0.02, delays=0.01/0/0/0.01, dsn=2.0.0, status=sent (forwarded as 174601C0AEC)
Feb 18 13:33:03 myserver postfix/qmgr[14721]: 16AD01C0AED: removed
Feb 18 13:33:03 myserver postfix/qmgr[14721]: 174601C0AEC: from=<root@myserver.mydomain.tld>, size=1480, nrcpt=1 (queue active)
Feb 18 13:33:03 myserver postfix/local[32803]: 174601C0AEC: to=<root@localhost.localdomain>, orig_to=<root>, relay=local, delay=0.01, delays=0.01/0/0/0, dsn=5.4.6, status=bounced (mail forwarding loop for root@localhost.localdomain)
Feb 18 13:33:03 myserver postfix/cleanup[35855]: 19FF81C0AEE: message-id=<20240218123303.19FF81C0AEE@myserver.mydomain.tld>
Feb 18 13:33:03 myserver postfix/bounce[28969]: 174601C0AEC: sender non-delivery notification: 19FF81C0AEE
Feb 18 13:33:03 myserver postfix/qmgr[14721]: 19FF81C0AEE: from=<>, size=3590, nrcpt=1 (queue active)
Feb 18 13:33:03 myserver postfix/qmgr[14721]: 174601C0AEC: removed
Feb 18 13:33:03 myserver postfix/cleanup[35392]: 1A7031C0AEC: message-id=<20240218123303.19FF81C0AEE@myserver.mydomain.tld>
Feb 18 13:33:03 myserver postfix/local[33361]: 19FF81C0AEE: to=<root@localhost.localdomain>, orig_to=<root@myserver.mydomain.tld>, relay=local, delay=0, delays=0/0/0/0, dsn=2.0.0, status=sent (forwarded as 1A7031C0AEC)
Feb 18 13:33:03 myserver postfix/qmgr[14721]: 19FF81C0AEE: removed
Feb 18 13:33:03 myserver postfix/qmgr[14721]: 1A7031C0AEC: from=<>, size=3738, nrcpt=1 (queue active)
Feb 18 13:33:03 myserver postfix/local[32803]: 1A7031C0AEC: to=<root@localhost.localdomain>, orig_to=<root@myserver.mydomain.tld>, relay=local, delay=0, delays=0/0/0/0, dsn=5.4.6, status=bounced (mail forwarding loop for root@localhost.localdomain)
Feb 18 13:33:03 myserver postfix/qmgr[14721]: 1A7031C0AEC: removed

I wonder where these mail are, because mail command always says "No mail for root".
Where should they actually go (maybe some misconfiguration?)?
And where would I set it up to send them to some external mail address (in plesk, since fiddling around with config files manually usually doesn't last long due to updates)?

 

[mow]

Feb 18 13:33:03 myserver postfix/bounce[28969]: 174601C0AEC: sender non-delivery notification: 19FF81C0AEE

I wonder where these mail are, because mail command always says "No mail for root".

It looks like they bounce, but the bounce notification bounces too, so nothing remains.

Where should they actually go (maybe some misconfiguration?)?

Normally there should be a line MAILTO="add@ress" so all output of entries below that line will be mailed to that address.

And where would I set it up to send them to some external mail address (in plesk, since fiddling around with config files manually usually doesn't last long due to updates)?

Just set a MAILTO= as described above.
However it is not recommended to forward to an address you don't control yourself because you won't get notification if there are issues with dns and/or spf, dkim, dmarc ...