How do I delete all Outlook data and reload Outlook

Hi ucamuk,

Thank you for using the Apple Support Communities! We understand you'd like to know how to delete all data associated with your Outlook account.

When it comes to adding your Outlook account to your iPhone, you can do that through the Mail app, or by downloading the Outlook app from the App Store. This helps bring data from your Outlook account over to your iPhone. If you want to remove that data from your device, you would remove the account from your device: Go to Settings > Mail, then tap Accounts > tap your Outlook account from the list > tap Delete Account. If you're using the Outlook application itself, you would delete the app from your device: Delete apps on your iPhone, iPad, and iPod touch

If you're actually wanting to manage your Outlook account's data, that would be something you would seek support for from Microsoft: Outlook help & learning - Microsoft Support

Take care.