I have a home server with its own domain name, been using it since uunet! days, and it has only one real user account, along with the usual *masters.
Up until the early 2000s, it ran fine over dialup. Somewhen in the 1990s, the amount of spam to non-existent accounts (bill123) began increasing, and once it hit 40,000 a day, dialup was no longer good enough. By then I could get satellite internet for my location in the boonies, and spam to those non-existent accounts kept increasing, hitting an average of around 600K messages a day, occasionally going over 1M. Yes, one million individual messages, all thrown out as soon as the nonexistent account name was given during the envelope phase, just drop the connection and wait for another. But sometime last year it did drop, and has been fairly steady at around 40-50K a day for several months.
I don't run any IP address blacklists. All I do is drop the SMTP connection if the account is not known.
My personal account by contrast has gone from 20-30 a day to 200-300 a day. These are messages to my one and only real account, but from unknown senders. I don't use any specific spam filters. I do white list email, with unknown senders going to a junk mailbox which I review every couple of days. Most are easy to confirm as spam, such as when I get 10-20 messages with the same silly subject (I doubt PayPal is going to send me that many dups of a warning message!).