> but a large percentage will be blocked as spam unless you use a well know relay even if you do everything right That's hardly a rule. You clearly will end up

> but a large percentage will be blocked as spam unless you use a well know relay even if you do everything right That's hardly a rule. You clearly will end up on a blacklist if you host from home or if your IP is already on a list due to previous spam activity, but of you run off a static IP in a decent colo and have a proper PTR record, it is more likely than not to be all OK. The 90% of inbound spam is still very effectively trimmed off by greylisting, i.e. postgrey if you are in postfix. I've been running my own mail server for close to 10 years now and it's really not a big deal.