Checking that email addresses entered using Google Forms are correct

If you use a Google Form to collect data email addresses, then you may want to use the Forms data-validation tool to check that the entered addresses are at least in the right "shape" to be email addresses.

How to turn on email-address validation in a Google Forms

Edit (or create) the question where you want the answer to be an email address.

Set question type as Text

Choose Advanced settings

Tick the Data Validation checkbox

Choose Text

Choose Email Address

Type in the message which should be shown to someone who enters text which does not look like a valid email address.

Complete and save the form.    When it is viewed, it should apply the email-address checking rules to any values that are entered into the fields that you turned validation on for.

What does address validation check

Google's email-address checking tool looks at the letters, numbers and other characters which are entered into the field, and decides if they look like a real email address.

What doesn't it check

The email-address validation tool does not try to send an email message to the address, so it does not know if is an address which is currently in use, and able to receive messages.

Examples

Mary@gmail.com - looks valid, will be accepted, even if there is no such address
Mary123@gail.com - looks valid, will be accepted, even if there's no such domain as gail.com
mary.gmail.com - does not look valid there's no @ sign, will be rejected
mary smith@gmail.com - does not look valid, because there's a space in the middle, will be rejected.

Also, Forms cannot know if the email address was entered by the person who uses it, or by someone else.   This is something you should think carefully about, in terms of what you do with the data.   Do not assume that all email addresses which you collect will have been provided by the right person.   Some will be wrong because of typos etc, while some will be entered maliciously.

What happens when someone enters an email address that doesn't conform to the rules.

They are shown the error message that you specified.

If the question is a required one, then they cannot move off the form until they enter a valid email address.