Cannot delete an Outlook folder

Question

Hello,

My Outlook account is compromised. Someone created a rule to forward all my received emails and a folder.

I've deleted the rule, reset password and log off in all equipment. But I can't rename or delete the folder, which is empty.
Have you any tip do handle it?

Answer 1

For a compromised Outlook.com account where a malicious rule and folder were created and the folder cannot be deleted or renamed, use a combination of security cleanup and folder management steps.

1. Secure the account so the attacker cannot recreate rules or folders
   • Ensure multi-factor authentication (MFA) is enabled on the account. A similar case of a malicious, self‑recreating rule stopped once MFA was put in place.
   • In Outlook on the web, recheck:
     • Settings → Mail → Rules and delete any suspicious rules.
     • Settings → Mail → Forwarding and remove any unknown forwarding addresses.
   • Use the “Sign out everywhere” option in the Microsoft account security portal to terminate all active sessions.
   • Review and revoke any suspicious app permissions in the Microsoft account security area.
2. Try deleting the problematic folder from Outlook.com (web)
   • In Outlook.com, in the folder pane, right‑click the folder and select Delete → OK to confirm. This moves it to Deleted Items.
   • In Deleted Items, expand the folder list (select the arrow next to Deleted Items if needed), right‑click the folder again and select Delete or Delete folder to remove it.
   • If the folder reappears, repeat the delete in Outlook.com and then, before it syncs back to the desktop client, delete it from the desktop Outlook client as well. A similar stuck folder issue was resolved by deleting the folder in webmail, letting it reappear once, deleting it again in webmail, and then deleting it from Outlook before it synced back.
3. If the folder is stuck under Deleted Items
   • In Outlook.com, open Deleted Items and use Empty folder to clear all items and subfolders.
   • If items or folders still persist, use Recover items deleted from this folder at the top of the Deleted Items view, then select Empty folder again. This can clear residual items that block deletion.
4. If the folder still cannot be removed
   • Confirm the folder is not a default system folder (Inbox, Drafts, Sent Items, Deleted Items), as these cannot be deleted or renamed.
   • If it is a custom folder and remains undeletable after the above steps and security cleanup, contact Microsoft support for Outlook.com, as the mailbox may need backend repair.

After these steps, continue to monitor rules, forwarding, and sign‑in activity for a period to ensure no new malicious rules or folders appear.

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References:

• Working with message folders in Outlook.com
• Cannot empty the Deleted Items folder in Outlook.com
• I have seen great advice for deleting the idtienphuoc1 Rule but none for stopping it from re-adding itself - Microsoft Q&A
• Hacker set up continuous draft ransomware email - Microsoft Q&A
• Cannot delete folder in outlook - Microsoft Q&A