i don’t remember the secure port numbers, but i thought 25 was plain text/insecure
i disabled CSF to test and the result is the same when sending from Thunderbird - The message could not be sent because the connection to Outgoing server (SMTP) mail.12bytes.org was lost in the middle of the transaction.
anyway, i opened 25 TCP in/out and restarted CSF - same deal
and again, both maillog and procmail.log files are empty
@ID10T - i restarted the server earlier and both dovecot and postfix now - problem remains; Thunderbird The message could not be sent because the connection to Outgoing server (SMTP) mail.12bytes.org was lost in the middle of the transaction.
Those are Debian-isms. Those files will never exist on a RHEL-based system.
You will either have a maillog or entries in the journal for each of the mail-related services. You will never have the same logs a Debian or Ubuntu system has. (Unless you explicitly configure the services to do so.)
i deleted /var/log/maillog, restarted rsyslog and postfix - they start normally, however a new maillog is not created
if i check the status of postfix i see activity (connections that should log), but nothing is logged
the debug link you offered provides info i don’t really comprehend, so i reinstalled postfix, enabled it, started it, and instantly there’s a 1.9 MB maillog file in which i’m seeing several lines like…
Jan 15 11:40:02 host postfix/smtpd: warning: SASL authentication failure: cannot connect to saslauthd server: No such file or directory
if i send mail to the server using my personal mail address to my account on the server, the server accepts the mail but i never receive them
if i send using my server account to: my server account, Thunderbird says…
The message could not be sent because connecting to Outgoing server (SMTP) mail.12bytes.org failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again
in both cases there is nothing in the mail queue and nothing is logged