Delete all
You should include a way to select many emails and delete them. I like to search senders and delete a strings. Delete all really helps when you get spam messages

Hi there,
Thank you for using Outlook Mobile and sharing your ideas with us. We really appreciate your support.
It is currently already possible to perform bulk action in the app. To do this, long press on an email until a checkmark appears at the left of it. Once you’ve selected multiple emails, you’ll then be able to perform the following actions: deleting, marking as read, archiving. A “Select All” option will also appear in the top right corner.
Having trouble finding the feature? Let us know through the Help section of the app in the Settings. (Settings > Help and Feedback > Contact Support). We’re here to help.
Thank you again for your support, we look forward to hearing more of your ideas very soon.
All the best
The Outlook Mobile Team
PS: Please use the Help Section of the app for any questions, we are not able to see replies to this address.