I don’t think of it that way, i see it as building better tools for detecting which connection sources are sending the most junk data, you can use statistical analysis based on the frequency of rate of write attempts.

content based filtering seems unlikely at this rate considering how the spam is currently operating.

I have a plan based purely on the rate of attempts, since we store that info in the rate limiter. This is fairly simple but will be even more effective once we start banning ips instead of just allowing 6 posts per minute, which still allows for a trickle of spam.

Once these tools exist other relays operators can use them. rspamd is the same idea and its extremely useful.

Im sure there will be more techniques into the future, but it’s a bare minimum for a public relay.