This may not be appropriate for your use case, but rotating the publicly facing email address when you get spam or on an interval may help here. For example hel

This may not be appropriate for your use case, but rotating the publicly facing email address when you get spam or on an interval may help here. For example hello-XXXXX@site.com (hello-a5b84@site.com, hello-jux8k@site.com, …). I believe most legitimate visitors send an email shortly after visiting a page with the address while spam emails often have a much longer lead time with new addresses (it takes time to get scraped, put in a database, and then get used). However this does mean that extended communication on that address and saved addresses will not work well.