Those lines are the ones that I think are relevant:
[17-Nov-2021 16:34:37 UTC] Connection failed. Error #2: stream_socket_enable_crypto(): SSL operation failed with code 1. OpenSSL Error messages:
error:1416F086:SSL routines:tls_process_server_certificate:certificate verify failed [/cpanel_data/icebook/public_html/ejournal/lib/pkp/lib/vendor/phpmailer/phpmailer/src/SMTP.php line 455]
[17-Nov-2021 16:34:37 UTC] SMTP Error: Could not connect to SMTP host.
As you can read, there is a problem with the certificate between your host provider and the smtp server (probably are not from the same company)?
It’s something difficult to trace.
Did you try with “smtp_suppress_cert_check = On”?
Is an undocumented variable that was introduced in 3.2 or so and it could do some magic here.
If not, your will probably need to ask first your hosting company telling them about your smtp server.
Cheers,
m.