Sometimes after changing your password, your mobile phone's built-in email application will keep prompting for your new password, but it doesn't accept it when you type it in. It either gives you an error, or keeps prompting without an error.
Officially, OTC suggests downloading and using the Outlook application from your device's app store, typically the Google Play store for Android devices, or the Apple App Store for iOS devices. The Outlook app has superior compatibility with Office 365 services and typically does not run into this issue. Windows mobile devices typically use the Outlook app by default and do not run into this issue as well.
However, we have found that removing your OTC email account from your device and then re-adding it to your device will sometimes get your email working again in your device's built-in application. Instructions for how to do this vary greatly depending on your version of Android or iOS, but you can drop by your phone's carrier store for assistance. OTC does not provide support for the built-in app.