Sending, receiving, and organizing email in Outlook.com
Hi,
Yes, you cannot sign in on new devices, but you can still send and receive emails if you are already signed in to the Outlook app or Outlook online before you change the security information.
On the Verify Your Identity screen, select I don't have these and follow the prompts to replace the security information.
After 30 days, your new security information will be updated, allowing you to verify your identity with the new information and sign in on all devices.
Let me know if you still need more help.