Microsoft Exchange: the cloud service behind Outlook access

Exchange works behind Outlook: it stores user data, manages email flow, syncs information with services such as Outlook and enforces account security policies. Outlook is the interface users see; Exchange provides the backend services that keep email, calendars and messages available.

For users, that distinction offers little comfort during an outage. If Exchange is unavailable or disrupted, people may be unable to access their email, calendar or messages through Outlook.

Microsoft posted updates about the incident on X. Mashable said it contacted the company with questions but had not received a response at the time of publication.