Microsoft Exchange is a Microsoft email service often used by businesses and academic institutions. Exchange synchronizes email between an Exchange server and your client email app, such as Outlook.

Microsoft says that it has mitigated an Exchange Online outage affecting customers worldwide, which blocked their access to emails and calendars.

In the Cached Exchange Mode, a copy of your mailbox is saved on your computer. The copy offers prompt access to your data and is often updated with the server that runs Microsoft Exchange. Cached mode ...