Issue with adding a long list of mail domains to deny list using *

What I have tried is to add a long list of temporarily/fake e-mail domains to the “Contact us” form I have created by adding it to the Fields/advanced/Denylist. Obviously I am trying to prevent use of such emails to be used for contacting me in my form.

This is the example of how the list looks like (there is a coma after each as suggested in the tooltip):

• *@safetymail.info,
• *@safetypost.de,
• *@saharanightstempe.com,
• *@salmeow.tk,
• *@samsclass.info,
• *@sandcars.net,
• *@sandelf.de,
• *@sandwhichvideo.com,
• *@sanfinder.com,

There is a total of 3752 domains at the moment.

However, when I click save form for the first time I am getting an popup error. After closing it and clicking save form again, form is saved.

Now the issue is that such saved form stops accepting all e-mail domains. I have manually checked for gmail, yahoo, or hotmail dot com. None of those is acceptable so obviously there is some kind of error/issue with saved form that contains this list.

My questions are if there is limit in how many e-mail domains we can add to “Denylist” and of course how to do it so the form works properly with the e-mail domains which are not on the denylist.

Thank you.