Outlook for Mac 16.86.1: Subfolder Contents Not Showing

I use the Outlook desktop app on my Windows PC to sync my email via IMAP from my domain hosted on IONOS. Everything was working fine until about a week ago, but now I'm facing an issue.

In Outlook, I can see all my emails that aren't in subfolders at the top level of my inbox, and I can see all my subfolders - but they're all empty. When I click on a subfolder, it says "Folder is Empty". However, I know those emails were there a week ago. I've checked and I don't have any filters set up that would hide them.

When I log in to my domain host's webmail, I can see all the emails in the correct subfolders. So, the emails are still there, they're just not showing up in Outlook.

Does anyone have any ideas what's going on?

There are several possible reasons why your subfolders are not showing up correctly in Outlook, especially given your IMAP setup. Here are steps to troubleshoot and resolve the issue:

  1. Reset Folder View: Navigate to the Folder tab, right-click, and select “Show all folders.” This might help ensure all folders are visible.
  2. Reset View: Click View > Change View and select Apply current view to other mail folders. This can help synchronize the folder structure and refresh the view.
  3. Recreate the Profile: Sometimes, recreating the Outlook profile can resolve issues related to subfolder visibility.
  4. Check Sync Issues: Go to the Folders pane at the bottom of the mailbox and scroll down to Sync Issues. Check if there are any errors related to the subfolders.
  5. IMAP Settings: Ensure that your IMAP settings are configured correctly and that the subfolders are set to sync. You can do this by checking your account settings in Outlook.
  6. Launch Outlook with a Switch: Try launching Outlook with the /resetnavpane switch, which can sometimes resolve issues with the folder navigation pane.

If these steps do not resolve the issue, you may want to consider further troubleshooting or consulting with the community for specific guidance tailored to your exact setup.