So I was Devving in Production :facepalm: and have somehow properly broken the link between my Windows 10 domain account and O365 exchange online account. If I go Settings -> Accounts -> Email & ...

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.

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 ...

Several users have reported an issue in which connectivity to Microsoft Exchange servers fails after the update to iPhone OS 2.1. Per Apple Discussions poster Jim Little: "Since upgrading to the 2.1 ...