When you open a sent message it says who it was sent by, not who it was sent to. I know who sent it. All of the messages in my outbox were sent by me. This is redundant information.
I recently had to go through a lot of messages in my outbox for a forum game and, opening them all in tabs, could not tell which tab had which person's message in it because they all said "Sent by Syndic" with no indication of who it was sent to. They all had the same title, so there was very little distinguishing messages from each other. This meant that I had to go through my sent messages one at a time, taking careful note of who the recipient was before viewing the message.
I know this is a niche change that won't actually affect many people, but I'm asking for it anyway.