Microsoft warned Outlook for Microsoft 365 users that clients might have issues connecting to email servers via Exchange ActiveSync after a January update.
Exchange ActiveSync is an Exchange synchronization protocol using HTTP and XML to let users access their email, calendar, contacts, and tasks.
EAS is enabled by default on new user mailboxes, and disabling it prevents users from synchronizing their mailboxes with mobile devices.
While the Outlook Team has yet to provide an explanation for this syncing issue, it's currently investigating and will provide a fix as soon as a solution is found.
Until this EAS syncing issue is resolved, Microsoft provides a temporary fix for affected users to revive their Outlook desktop clients.
This requires reverting Office M365 Click-to-Run installations to an unaffected Office build or switching to an Office Channel that does not have this sync issue.
After the version revert process is finished, launch Outlook to check if it's operating normally again.
Microsoft is also investigating an issue triggering Outlook security alerts when trying to open.
ICS calendar files after December 2023 Patch Tuesday Office security updates are installed.
Redmond fixed another known Outlook issue this month that was causing connection issues for desktop and mobile email clients when using Outlook.com accounts.
In December, Microsoft addressed two other bugs, one behind email sending issues for users with lots of folders and one causing Outlook to crash when sending emails from Outlook.com accounts.
Microsoft Outlook December updates trigger ICS security alerts.
Microsoft says Outlook apps can't connect to Outlook.com.
Microsoft fixes Copilot issue blocking Windows 11 upgrades.
Microsoft working on a fix for Windows 10 0x80070643 errors.
Microsoft fixes connection issue affecting Outlook email apps.
This Cyber News was published on www.bleepingcomputer.com. Publication date: Fri, 09 Feb 2024 18:00:14 +0000