A Microsoft file hosting and synchronization service.
Hi @susie becker , Welcome in Community
Try to remove and Re-add the Account in this way:
Go to Settings > Mail > Accounts, select your Hotmail account, and tap Delete Account. When adding it back, select Outlook.com or Exchange (do not select "Other") to ensure the server settings authenticate and configure automatically.
If you use the standalone Microsoft Outlook app instead of the default Apple Mail app, open the app's Settings, select your account, and tap Reset Account to clear the cache without deleting emails. Alternatively, delete and reinstall the app from the App Store.
Then, check to have the latest iOS version available: Go to Settings > General > Software Update to ensure your iPhone is running the latest available software
Let me know how it goes
Elvis