It has been brought to my attention that all threads that people are replying to are automatically being subscribed to. I understand that this can be annoying (especially if the emails are being sent to your work) - so - to fix this issue: On the left side of the UserCP screen, you will see "Edit Options". If you click on that (or right-click, open in new window), under "Messaging and Notification" there is a "Default Subscription Mode" with a drop-box of options. Set that to "Do not subscribe" and then save the settings. Once that has completed, you will see all the threads that you are subscribed to (once the page refreshes) and then you can manually unsubscribe from them all.