I've had to deal with this with e-mail verification links and Auth0. The user clicked the link after getting it in their mailbox but then Auth0 throws up an error page because the e-mail address has already been verified (by Outlook scanning). The problem becomes worse if for some reason the mail ends up in the junk mail folder so the user thinks they've never received the mail but when you check it looks like the e-…
I had a customer who had some sort of software that followed the link in the email we sent (no big deal so far), and THEN would follow every link and button on that page. We had a handy quick decline and accept button on there so they were auto declining things… I didn’t hate email until I got into web development….
How about having a input field asking for the email again to double check?