Sending, receiving, and organizing email in Outlook.com
Hi,
May I ask if you're currently using a web browser on your phone or the Outlook app? If you are using outlook app or any Mail app, please try to log out of your account, then restart your device. Log in to your account again and observe for a few hours if emails are coming or syncing.
If the issue persists, try to clear the cache and data of your app.
If nothing works, please try uninstalling and then restarting your device. Install the app again and sign in. Observe for a few hours and see if the emails are syncing.
Regarding the credentials needed on your phone, is it an email asking for your credentials? If so, please do not click any link or respond. There is a possibility that this email is a scam or phishing.
Please check the email address and the content.
I look forward to your response.
Stay Safe!