On Mon, 2017-06-19 at 15:26 -0400, Fred Smith wrote:
I can figure out some simple scripting to turn the maillog entries into times since the epoch, or other formats, if needed, but I have no experience with the various graphing tools availabe, or even what (or where) they are.
mrtg would be a simple option. It's designed for graphing network traffic but can be used to graph anything you like. There are examples in the contrib directory.