>On postfix itself you can use regular blocklists to prevent such
obvious IPs.
For the other services like imap etc. it helps to use fail2ban.
I have all filtering that I know of off right now. I am just trying to
establish incoming communication with other SMTP clients right now. Once I get
SMTPD services running and delivering incoming messages to the virtual
mailboxes, I will work on fetching the mail through dovecot. Then at last I'll
address blacklisting and spam after I get my server basically working.
