As far as I know, there is no option to display this sort of info anywhere. So I would have to either program it myself or pay someone else to do it. Neither one is likely to happen anytime soon, I think.
The maximum number of messages anyone can store is 70, which includes received and sent messages. I suggest that periodically everyone needs to go through and weed out all of those old messages anyway.
Sorry, but this is just something I guess everyone needs to consider as housekeeping for their account here. I could set it to a higher figure, but the database for this message board alone is already just over 168 megabytes. So I think some incentive is needed to whack those old messages every now and again.
Later......