Most of the messages I receive are the automated "successful trade" ones which only require quick skim reading - but I have to go into each message in turn, then go back to the overview and then into the next message. This usually takes longer than I would like.
It could be made easier with a "previous/next message" option to avoid having to go back to the overview between each message.
Or, if the subject line was more informative (just including the type of goods would help a lot), I wouldn't have to go into the messages at all.