You can't send or reply email from Outlook.com, Office 365, or Exchange in iOS 11.0 Mail app

Applies to: Exchange Server 2016 Standard EditionExchange Server 2016 Enterprise EditionExchange Online More

Symptoms


In the native Mail app (Mail.app) on your iPhone or iPad, you can't send or reply from your Outlook.com, Office 365, or Exchange Server 2016 email account after you upgrade to iOS 11.0.

Note These issues don’t occur in iOS 10.x.

Cause


This issue occurs because the Mail app on iOS 11.0 is incompatible with Outlook.com, Office 365, and Exchange Server 2016 running on Windows Server 2016.

Resolution


To resolve this issue, update your device to iOS 11.0.1 or a later version. 

References


For more information about this issue, see this Apple support website.