Filtering / Excluding certain Email addresses in App Registration Process

Hi, I have setup a registration process on my app where anonymous users need to sign up to gain access to different services. In the e-mail section of my registration form the user inputs an e-mail address required for registration, how can I exclude certain email suffixes (eg.,, etc) from being accepted as we want to exclude these users using these addresses to gain access to our app.
1 answers

I'd create a microflow on the 'save' button and validate the string they put in there. I would not go with a regular expression in a simple case like this, just take the part of the string after the @ sign and check it against the disallowed list that you have. You can either put this disallowed list in a constant or as a domain entity, the latter will perform slightly worse but is easier to manage.