Reminder: Your Microsoft 365 apps soon won't work with Internet Explorer 11

Microsoft warns customers to prepare for their apps to stop working properly in IE 11.

Microsoft has issued a reminder to Microsoft 365 customers that its web apps will not work properly when using Internet Explorer 11 from August 17, 2021.

Microsoft warned customers in February to prepare for degraded support for IE 11 in its key Office apps from August 17: it first announced the end of M365/O365 support for IE 11 on August 17, 2020. 

"Beginning August 17, 2021, Microsoft 365 apps and services will no longer support... IE11 and users may have a degraded experience, or be unable to connect to, those apps and services. These apps and services will phase out over weeks and months to ensure a smooth end of support, with each app and service phasing out on independent schedules," the latest warning notes.

"If you encounter issues while accessing Microsoft 365 apps and services from IE11 after August 17, 2021, support will be unavailable. Additionally, you should expect no new features and that your daily usage experience could get progressively worse over time until the apps and services are disconnected."

Separately, it's also dropping support for IE on many versions of Windows 10 on June 15, 2022 and encouraging customers to move to the new Chromium-based Microsoft Edge browser. 

Edge has an IE11 compatibility feature for displaying Outlook content, consisting of a complete version of IE's old Trident engine that runs in an Edge tab. As ZDNet's Simon Bisson points out, this might be fiddly for admins to maintain and near impossible for anyone restricted to working from home. 

Microsoft notes in an updated blogpost there will be two separate experiences for Outlook Web App users, depending what type of account they're using Active Account Directory (AAD) or Microsoft Accounts to log in. 

"Users logging in with AAD accounts will still receive the full OWA experience but will not receive new features beginning August 17, 2021, while users logging in with Microsoft Accounts (MSA) will be redirected to the Outlook Web App Light experience," Microsoft says. 

There's also some changes due for Share Point features like Open with Explorer and View in File Explorer to access document libraries. 

"To avoid disruption, these customers will be able to use these features for now when they go to a document library in IE11. These features remain in maintenance mode and aren't receiving further development," Microsoft notes. 

However it is encouraging all customers to move to a modern browser and prepare SharePoint for the end of support on IE11. Microsoft has posted documents to assist admins to prepare SharePoint environments for it when it comes.