How to Restrict Users From Entering Email IDs of Certain Domains

You can restrict users from entering email IDs of certain domains in your survey. This can be done by enabling the Blocking Emails setting:

Here's How to Enable the Blocking Emails Setting in Your Survey

Go to a survey's Settings >> Advanced and enable "Blocking Emails." Once enabled, enter the domains that you want to block, separated by the comma sign. For example, yahoo.com, gmail.com, and so on. When you're done, click "Save" to apply the changes.

That is all about blocking emails in ProProfs Survey.