CRM 2015 - Installing the CRM Outlook plugin on multiple machines.

Hello,

Our sales manager works off of multiple different machines.  When installing the CRM plugin on more than one machine we have noticed issues.  

1. Is it possible to have the Outlook plugin installed on multiple machines and work? 
2. If it is, would you point me to a place where I see how to set it up?
3. Does anyone know how many machines it can be installed on for a single user and still work?

Thank you all for your time!