​@Sri1 

This is not possible with Airtable’s forms, but it is possible when using Fillout’s advanced forms for Airtable.

You can create a login page for your form by using Fillout, which will give you these features:

1. Fillout will allow you to validate email addresses based on a pre-approved list of email addresses that you have stored in Airtable.
2. You can verify & confirm that the user is typing in a valid email address.
3. You can restrict the logins by SSO or email domain or your pre-approved list of email addresses.
4. You can limit form entries to one entry per person.
5. And much more.

Hope this helps! If you’d like to hire an expert Airtable consultant to help you with anything Airtable-related, please feel free to contact me through my website: Airtable consultant — ScottWorld

Hey there, with our miniExtensions Form's login feature you can achieve exactly this. Essentially, your email master list would be a table with email addresses, each in their own record. You would then set up the miniExtensions Form to use the email as a login field, which means that each user would log in to the record associated with their email address in the master list table. From there, they can add any data you need to their record, or to other tables as well using linked record fields. By default, an error is shown when an email is entered that's not on the list, but you could also choose to let them create a new record in the master list table anyway! Our form also has some security features, like email verification (with a one-time code sent to the user's email when they try to log in) or additional login fields like passwords. There's a lot of functionality to discover!

You can try all of this out now by creating a free account! 🙂