Microsoft: Outlook clients not syncing over Exchange ActiveSync

By Sergiu Gatlan February 9, 2024 12:57 PM

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 (EAS) 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.
“After updating to Version 2401 Build 17231.20182 Outlook stops connecting when using the Exchange ActiveSync (EAS) protocol,” Microsoft said.
“We have to use Activesync in order to connect to our cloud-hosted email server. Other syncing may not be impacted,” one impacted user said.
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.

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