@kirby @dcc @PeachySummer You will he get spam anyway. Bots will scan your IP, perform a reverse DNS lookup, get your domain and spam the default addresses like webmaster, abuse,...

You can always set it up later if you want. But since you will need to setup dmarc and dkim anyway, it's better to also setup spamassassin. It's like a single change in postfix after dmarc/dkim and one sieve rule in dovecot.