Check if Outlook MAPIFolder is visible?

Question

When I iterate through all Outlook folders (in a C# Add-In) I see folder names like:

• Yammer Root
• Sync Issues
• Subscriptions

These folders are not visible in Outlook. I like to check in my code if the folder is visible or not but I don't find a property like Hidden or Visible.

MAPIFolder folder has properties like:

• folder.DefaultItemType
• folder.Name

but not hidden.

How can I find out in my c# Add-In if folders are hidden or not?

Answer 1

You will need to read the PR_ATTR_HIDDEN MAPI property (DASL name http://schemas.microsoft.com/mapi/proptag/0x10F4000B ). You can read it using MAPIFolder.PropertyAccessor.GetProperty .

You can see that (and other) property using OutlookSpy (click IMAPIFolder button)