> ChatGPT
For debugging Koozali SME it is probably worse than useless as it doesn't understand properly about events, actions and templates. Koozali is not quite a standard Linux server. Treat the information ChatGPT gives you with extreme caution. My web dev tried it and half broke my server before his changes were lost again on a reconfigure.
You are better off searching and reading here, and the wiki. This has been answered many times before (so much for ChatGPT then.....)
Logs for your incoming mail are here:
/var/log/qpsmtpd/current
Best thing to use is Geoip to block the worst offenders.