Eureka!
After wasting HOURS, and no reply from MSFT technical support, this worked for me:
- Login to outlook.live.com
- Settings (gear) > Options > General > Mobile Devices
- Select iPhone and REMOVE ("-" icon)
- Power off iPhone
- Power on iPhone - device should attempt to re-register with Microsoft
- Look for email with subject, "ACTION REQUIRED TO SYNC EMAIL"
- Click "Continue using this email app"
This should open default web browser, and display a success message:
"We've noted that you'd prefer not to use the Outlook Mobile app. Outlook.com will resume syncing with your device."
Go back to screen from #2, and click the pencil icon for device details.
Look for -- Access state: Access granted
Note to MSFT: I want the option to use EITHER built-in iOS contacts/mail/etc. and/or your Outlook app.
(However, my companies MDM Mobile Iron software will not permit the use at this time!)
Until I did this, none of the SYNC emails from Microsoft had usable URLs and device remained Quarantined.
YOU ARE THE MAN!! Thank you. It works just like you said. After days of trying lots of things this worked. :)