Solve an issue with "ghost" folders

This guide explains how to delete folders that appear grayed out on the Web Mail Infomaniak app (online service mail.infomaniak.com) or in certain email software/clients like Apple Mail, Mozilla Thunderbird or Microsoft Outlook.

Ghost folders

Some email clients like Microsoft Outlook allow you to create subfolders of non-existent folders. For example, it is possible to create the folder /abc/klm/xyz even though the folder "klm‍" does not exist.

On Mail Infomaniak or in other email software/clients, ghost folders like the folder "klm" in this example appear greyed out and cannot be deleted directly.

To delete these ghost folders, it is necessary to delete their subfolders first (in this example: xyz).

Stubborn folders

If, when consulting your Infomaniak email address on Outlook, ghost folders appear and cannot be deleted because they reappear instantly, here is a procedure recommended by Microsoft to resolve this issue:

Reset the IMAP cache

To do this:

• Close Outlook.
• Access the folder where your Outlook data files are stored: C:\Users\[Your Username]\AppData\Local\Microsoft\Outlook.
• Find the .ost file associated with your IMAP account (e.g. Infomaniak) and delete it (the file will be automatically recreated when Outlook is reopened).
• Reopen Outlook and let it resynchronize your emails and folders.

Search for hidden folders in Outlook

To do this:

• In Outlook, go to the "Folder" tab and select "IMAP Folders".
• Click on "Request" and search for the ghost folder.
• If you find the folder, try to unsubscribe from it, then delete it.

Use the MFCMAPI tool

MFCMAPI is a tool that allows you to manage mailboxes at a low level and delete stubborn folders:

• Download MFCMAPI from the official site (choose the x86 or x64 version according to your system).
• Run MFCMAPI and go to Session > Logon. Select your Outlook profile.
• In the MFCMAPI window, expand the mailbox associated with your IMAP account and locate the ghost folder.
• Right-click on the folder and select "Delete folder". Choose "Hard Deletion" for permanent deletion.

Check the properties of the folder in Outlook

To do this:

• Right-click on the ghost folder in Outlook, then select "Properties".
• Check if there are any unusual settings. Reset or modify the settings if necessary, then try deleting the folder again.

Recreate the Outlook profile

If the previous steps fail, recreating your Outlook profile can be an effective solution:

• Back up your important data before proceeding.
• Go to Control Panel > Mail > Show Profiles > Add.
• Follow the instructions to set up a new email account.
• Set this new profile as the default profile and open Outlook.
• Check if the ghost folder persists after creating the new profile.

By following these steps, you should be able to resolve the issue of ghost folders in Outlook IMAP.