Does our whole company have to switch?

Yes, if you’re signing your company up to run its email on HEY for Domains, everyone at your company needs to switch.

Why? Because of the way MX records and email domain hosting works, you can’t host corporate email across multiple email providers. The same is true for G Suite/Workspace or Outlook — every employee needs to use the same email provider if their email address has the same domain name (@ourcompany.com, etc).