Outlook app won’t open on iphone

(1) Try and Force Restart your iPhone EXACTLY as shown below and see whether that resolves the issue:

• Press and quickly release Volume UP button
• Press and quickly release Volume DOWN button
• Press and Hold the SIDE button until an Apple logo appears and then release the Side button (Can take up to 20 seconds. (DO NOT release Side Button when invited to Slide Power OFF). 

(2) If the above does not work then - Delete the Outlook app and then reinstall it from the App Store. You may to set up your email address(es) if you choose this route.

Axel F.

Siri Pops up probably because there is too much delay in between pressing and releasing the three buttons. Please try the procedure again and exactly as shown in my post. If you are unable to then another method is to simply shut down the iPhone and start it again. Open Settings ➔ General ➔ Shut Down (Scroll all the way down).

Axel F.

Best bet for you, at this point, is to delete the Outlook app. Shutdown and Restart the iPhone. Then download the Outlook app again and set up the email account(s) again.

Axel F.

You are welcome.

Axel F.