This isn't a priority, just an idea :)
It would be nice to have a mail box to discuss with allies, friends or foes. We're not all connected at the same time and we don't always read all in the shoutbox.
I know that not everyone likes to Role Play, but there is interaction involved. So, to give an example by experience: an alliance has added me to their list for war out of the blue and I would have liked an explanation for why I was attacked. Actually, I was more bothered by the fact that there had been no exchange than the fact I was being attacked :p
So, I thought that if there was a possibility to add a line of explanation when clicking on the button "war", it would be helpful (the explanation could go from "your territory is expanding too fast", "I want to up the levels of my hero", to "I want total domination" or "I need resources badly" or "I wanted to test my army).
Or, if we had a mail box In Game, you could mail a RP message to your opponent/friend/ally just for the fun of the exchange.