Email Tracking Software

I'm needing a email solution and not sure the direction to take - or the solutions that may be available. Nonetheless, I am looking for email software that would allow me to manage emails based on login. e.g. If rep1 and rep2 are logged in and both are checking emails that come into our office, and if rep1 clicks on an email to open it rep1 then becomes the owner of that email and I am able to track the activity of that email based on rep1. Are there any solutions out there like that?

Are there any customizable solutions out there?

Any thoughts on this would be helpful, thanks.