Best solution to integrate outlook emails to CRM?

I think Celigo has a tool for this

Another tool to use is SuperSync. Im not sure the difference between that and Celigo cloud extend, but it provides a widget within outlook to look up the customer related and hit a button to synce emails. It BCC's them to that customer card in Netsuite, you can select that one email or turn on auto sync after selecting to always automatically send those emails into Netsuite's notes. Also works with calendar events. Costs $5 a month per user

Celigo