ExRCA: Analyzing Messages via Headers

ExRCA (https://testconnectivity.microsoft.com/ or http://www.exrca.com/ [Redirects to the former.]) has a feature that you can use to analyze where message delays may have occurred, aptly named 'Message Analyzer'.

You'll get a table with each hop that the message passed through and the time between each, like the following:

You can also get the Analyzer installed as an App for Office.