Postfix on deprecated MacOS server will not deliver mail [closed]

I just started working at this new job and I'm 4 days in. I've inherited this wonderfully ancient Mac server. The department relies on this server to provide internal email. From what I've recon'd so far, I have postfix running. Email clients are able to connect successfully and Postfix is holding on to incoming and outgoing mail unless I manually clear the queue periodically. I've done a lot of research online, but a lot of the data is years old, of course due to the age of this setup. I installed webmin to get a visual GUI look at things. Staff want to send these emails internally and be able to have them go out over the web as well. It was working up until last Thursday, but I made no changes or updates.

Here are all the changed settings on the server, everything else is default:

Postfix Version: 3.2.2

main.cf non-default parameters:

biff    nocompatibility_level     2debugger_command    PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin ddd $daemon_directory/$process_name $process_id & sleep 5html_directory  /usr/share/doc/postfix/htmlinet_interfaces     loopback-onlymail_owner  _postfixmailbox_size_limit  0manpage_directory   /usr/share/manmessage_size_limit  10485760mynetworks  127.0.0.0/8, [::1]/128queue_directory     /private/var/spool/postfixreadme_directory    /usr/share/doc/postfixrecipient_delimiter     +sample_directory    /usr/share/doc/postfix/examplesserver_config_directory     /Library/Server/Mail/Config/postfixsetgid_group    _postdropsmtpd_client_restrictions   permit_mynetworks permit_sasl_authenticated permit

main.cf parameters defined as per defaults:

command_directory   /usr/sbindaemon_directory    /usr/libexec/postfixdata_directory  /var/lib/postfixinet_protocols  allmailq_path  /usr/bin/mailqnewaliases_path     /usr/bin/newaliasessendmail_path   /usr/sbin/sendmailsmtpd_tls_ciphers   mediumtls_random_source   dev:/dev/urandomunknown_local_recipient_reject_code     550

I am truly at a loss. I've restarted and stopped/started postfix, reloaded its config.

I see Dovecot on the server too, but all of its config files are empty.

Any thoughts or help your collective knowledge can suggest will be most appreciated.