This may not be a main concern of yours, so you know who to send it to.
It's a small problem I am facing because of my on and off play style, that I might log in 2 till 3 times a week, and whatever we discuss in our guild gets lost into the endless web. That's easily righted by logging in every day, but that just ain't how I play. I'd love to keep up with what my friends in my guild answer, so our messages don't resound into nothingness without being read by the one meant to hear them. Could you create a back log of say 2 weeks, that keeps track of all the messages, to be read if requested?
I am sure with bigger guilds there are lots of messages that easily swamp an use for this, but there just ain't only active players in this game, so this might help other players like me, who just can't use the short message retention.
Thank you for reading this far, I really hope this gets implemented.
-slipknots