It does not matter what email address or name I put in my form, it is always rejected as spam.
I have two Akismet fields as you recommended here:
[text* your-name akismet:author]
[email* your-email akismet:author_email]
I cannot ask visitors for author URL as the form is intended for general enquiries.
I have tried on two different websites, and the problem occurs on both.
Many thanks for any advice.