Deleting mail messages

How does one delete sent messages?...there is a delete button to delete messages in the in box but no delete button to delete sent messages. Am I not seeing the forest through the trees or what?..any help will be appreciated...🙄

Not that I really know what I am talking about, but I think that the Sent messages do 1 of 2 things. Either automatically delete after a timeout set by the programmers, OR, dissapear when the recipeint decides to delete them.