Windows Mail works along with your Mcafee Anti Spam system. Spams are checked and moved to a Spam folder automatically in Windows Mail. That Spam Folder belongs to MCafee. Sometimes , the folder might get corrupt and MCafee then stops resending those emails from Inbox to the Spam Folder.
The size of the spam folder might be huge , hence at times while deleting those emails manually from the SPAM folder , Windows Mail might crash. Here is the workaround:
1.) Reboot system in Safe mode
2.) Open Windows Mail. Goto Options from the menu and then on to maintenance , click on Store Folder and copy the path.
3.) Navigate to the store folder path > Inbox and then delete the Mcafee Spam Folder. Reboot system in Normal mode
4.) Reopen Windows Mail. The folder would be recreated but you will still see the emails (the content would be empty). Select them by pressing Ctrl + A and delete them.