Mail Switch is a Chrome extension for mixed IT environments consisting of G Suite and Outlook or other e-mail services. The common practice is usually, working in G Suite and using Outlook as their primary e-mail service. This presents a problem using email functionality in some of the Google services. E.g using the functionality to email all students in Google Classroom or their guardians.
Mail Switch lets your administrator configure settings for the entire domain or on a user level. This extension will redirect users from Gmail to an Outlook client or a web access instance. By using the extension you are not bound to Gmail while using G Suite and you can freely use any other supported mail service. It has preconfigured functionality for Outlook, but can be configured with any mail client which is installed on the computer. This gives the user the ability to use the full functionality in Google Classroom and Google Contacts even though not using Gmail.