G'Day Carlos We started hosting own SMTP servers on IBM OS2 using a BBS. Long before retail NET was in Oz. Fast forward to today and we have a DB with millions

G'Day Carlos We started hosting own SMTP servers on IBM OS2 using a BBS. Long before retail NET was in Oz. Fast forward to today and we have a DB with millions of IPV4 address and have never used IPV6, cloudflare or a 3rd party to 100% stop spam like we do day in day out. You are absolutely right, there are a lot of criminals you are wearing suits who are selling snake oil. We have X simple rules, one is that inbound port 25 sessions from spammers are put to sleep and we give them a very poor service. Our servers seem overworked and they often go away never to return. I read your blog post and from approx. 30 years experience including SMTP at gov.au and gov.nz content filtering does not work. Our NoSpamAccepted ( NSA ) AI powered SMTP servers use the network to stop spam. How many domains & sub-domains are you self hosting ? TIA KG BTW - We have never been in the BLs as we only relay our outbound