Good Afternoon Fellow Power Users!

Thus far the forum has been helpful so I am going to try and get info on something that I have been totally unsuccessful at in the past. 

I would like to create a customer saved search that uses details of the most recent email logged as part of the criteria.  Long story short....  We had some terrible sales reps that were not taking care of their leads/prospects correctly.    I need the criteria to pull any lead/prospect whose last email logged was FROM the customer/prospect TO us (either a specific email address or contains our domain).  There are many other areas where we could apply this method in similar fashions so I would like a very detailed answer as to how to write the criteria.  I imagine it