After doing the same since 2003, out of ~200 email addresses used 18 are listed on HIBP, ~15 receive dozens of spam emails a day (or rather: would receive if I hadn't completely blocked them) and ~10 see almost non-stop login attempts from all around the world via IMAP and SMTP.

Address linked with "mailto:" on a contact page had to be blocked after a few years. Same with WHOIS addresses (published before there were sane privacy rules for those). Address with "@" and "." replaced with "at" and "dot" receive no spam at all.

Summed up, there are a few hundred inbound messages a day. Spamassassin and some basic postfix rules filters almost all of them. One or two a month get through.