BleepingComputer.com: Outlook 2007 recieves a new messsage attached to an old one

Over the past several months, maybe longer, I have noticed that an unread message exists in my juno.com folder inbox. When I apply the "show unread messages only" filter, I can find the message. However, it is dated several months ago and is always from disqus.net. I regularly post on my local newspaper's forum and it uses Disqus. I received two such messages today. However, I noticed that in each message is a new message that is not from disqus, but is attached to an original message that I received months ago concerning a rely to one of comments. I am using Outlook 2007 and have 5 POP3 accounts that I first receive to the Inbox then move to the various folders. Sometimes, I will receive the original email again, without any attachment. It's hard to say how many of these I have received and/or who sent them since I usually deleted them. Any ideas on what is happening?