What are IMAP and POP? - Microsoft Support
IMAP and POP are two methods to access email. IMAP is the recommended method when you need to check your emails from several different devices, such as a phone, laptop, and tablet.
Applies To:
Outlook for Microsoft 365, Outlook for Microsoft 365 for Mac, Outlook 2021, Outlook 2021 for Mac, Outlook 2019, Outlook 2019 for Mac, Outlook 2016, Microsoft 365 admin, Outlook.com, Outlook Web App for Office 365 operated by 21Vianet, New Outlook for Windows, Outlook Mail for Windows 10