Why doesn my mail go away when I delete it using mywaterloo?
Even if you have marked the mail for deletion, it may not have been deleted permanently. Click on “Show Deleted” to see if your messages are hidden rather than deleted. You can then click on “Purge Deleted” in order to remove them permanently. For the mywaterloo help on this topic, see: http://www.nexusmail.uwaterloo.ca/horde/contact2/faq.