Since the password has already been changed, forwarding was disabled, and an unknown device was removed, the next checks are the ones most commonly left behind after an account compromise:
- Check mailbox storage first. If Microsoft cloud storage or the mailbox is full, Outlook.com cannot send or receive email. Messages sent while storage is full can bounce back to the sender and are unrecoverable.
- Check Outlook.com mail settings on a computer:
- Open Outlook.com settings.
- Go to Mail > Rules and remove any rule that deletes, moves, or redirects mail.
- Check Forwarding and make sure nothing is still forwarding or redirecting messages.
- If IMAP-related settings were changed during the compromise, remove anything suspicious there as well.
- Check account security settings:
- Review recent sign-in activity on the recent activity page to see whether there are still unfamiliar sign-ins.
- Check aliases and sign-in preferences, and remove anything not recognized.
- Remove existing app passwords if any are present.
- Use Sign out everywhere so any remaining sessions are forced out. One accepted support answer notes this can take up to 24 hours to take effect.
- Check account recovery-related settings that are commonly changed after a hack:
- Connected accounts
- Forwarding
- Automatic replies
- Check whether the account is temporarily blocked because of unusual sign-in activity. A blocked Outlook.com account can prevent normal mail flow. Use the Sign-in Helper to unblock it if needed.
- If the account password was changed on the website and mail is also used in Outlook apps, update the saved password in Outlook so the app can sync again.
Based on the steps already completed, the account is not necessarily still hacked. A more common cause after recovery is that a malicious rule, forwarding setting, alias, app password, blocked state, or full storage is still affecting delivery.
If unfamiliar sign-ins still appear on the recent activity page after the password changes and sign-out, treat the account as still compromised and continue recovery through the Microsoft account recovery flow.