the junk folder is most likely the dangeroust folder of your mail inbox. So every email in it should be treated like it could harm the user or the computer.
But every time I check my junk mails my Bitdefender is going crazy. I think it is about downloading favicons.
So please stop any downloads concerning junk mails. Even if it is only the favicon.
It was also possible for me to click on links inside the junk folder. Disabling clicking any links would be also great. Instead of opening the link there could be a message that this mail is junk and could be dangerouse. (Same for attachments. But I havn’t tested if they could be opened.)