Trevor,
Regarding the "most of the 15 sent mails" being in your trash, was that only for the emails for which you received replies? Did you delete those replies?
If so, then the entire email conversation, which includes the emails you sent to those people whose replies you deleted, will "appear" when looking in your trash because they're part of the same conversation. If you turn conversation view off, perhaps just the email replies that you deleted will show there. Come to think of it though, if you had conversation view on when you deleted replies then you probably deleted the entire conversation.
Or, if you didn't delete those replies, then this attempt to explain what you're seeing is not applicable.
Kenneth