If you want a custom domain (e.g., name@yourbusiness.com) instead of @outlook.com.
While you can send and receive emails for free, there are significant differences between the no-cost versions and the paid versions included with a Microsoft 365 subscription. 1. Advertisements is ms outlook free
If you manage multiple calendars, huge attachments, or complex folder systems. You want more storage: If you are hitting the 15 GB limit. If you want a custom domain (e