You can change your Outlook password from the Microsoft account security page. If you're using the app, it'll ask you to ...

Are you receiving—Couldn’t sign you in. This browser or app may not be secure. Try using a different browser. If you’re already using a supported browser, you can try again to sign in—when trying to ...

To switch between inboxes, tap the Profile icon in the upper-right corner and choose an email address. Another option is to install the provider's app. Outlook and Yahoo have their own apps. This ...