What is happening? In order to connect the Skype for Business client to Exchange Online mailboxes using the preferred Exchange Web Services (EWS) protocol, Modern Authentication will be enabled throughout the Skype for Business environment.
When is it happening? Tuesday April 11 at 10 a.m.
What is the impact? There is no impact to any users who are already signed in. For users who are signing into the Skype for Business client for the first time, a typical modern authentication prompt via Microsoft 365 to your Exchange Online mailbox may be presented.
No other impact is anticipated, and the change will be closely monitored to ensure all known client types still function as required. This change will only be reversed if there are any significant issues.