What is the enhancement in mind? How should it look and feel?

Is it possible to add a new module which allows to save messages between session and display them when you login the next time. so that you are able to read messages that you weren't able to read because you were AFK for too long(auto logout).
regarding the configuration i am thinking of following settings:

Regarding the overall amount of saved messages:
Save the last xx minutes before logout. OR
save the last xxx Messages before logout

and (if possible) options regarding the channel of the saved messages:
whispers(including battle.net whispers), guild messages, etc. and the user cann pick which channels are stored.

Or it may also be a good idea to merge this with the history module since there are already similar options.

Maybe this addon would be usefu for implementing thisl: http://wowinterface.com/downloads/info20287-ChatHistory.html

Thanks in advance