Check comma separated email address is valid

Loop through a Google Sheet cell of comma-space separated email addresses and check their format is valid, otherwise display a user popup.

The following Google Apps Script is designed to loop through a Google Sheet cell of email addresses that have been separated by a comma and space. It then uses a regular expression (regex) to confirm the email address meets the correct formatting criteria.

This code was developed as a way of implementing additional checks when asking users to be precise in how exactly they enter multiple email addresses. So if they were to forget the space for instance it could alert them, before the rest of the code risked failing as whatever task it was designed to do.

Source: The Gift of Script: Check comma separated email address is valid