Thanks for the insightful information! I was trying to look for a solution that solves for the concerns you shared.
So, I've included this in a Marketo LP and ran a few tests. It's properly blocking out "gmail.com," "aol.com," etc in line 14. But, it's not blocking emails from that larger list you shared, from freemail/free.txt at master · willwhite/freemail · GitHub
Can you advise on how we can block all emails seen in that list?
First you'd need to make sure the free.txt file is uploaded to Design Studio (for forms on Marketo LPs) and/or to your corporate site (for embedded forms).
One more question - if we use this code, how do we get the form to provide an error message to the user? "Please provide a business email address."
Sanford Whiteman - I'm trying to get this code to work on a Marketo LP first - and it's having no effect. Is there other code that needs to go around the sample you provided that a developer (which, as you know, I'm not) would automatically be adding? I did put it the whole thing inside <script> </script> tags.