We (GoodLife Realty-- our associated brokerage) use Realvolve for CRM and Google Apps for internal communications and email platforms. We are quite happy with these actually and would highly recommend them to you.
In our day-to-day operations as The Paperless Agent, we use Infusionsoft to manage our customer interactions, but we don't recommend it for real estate because it's just not equipped with the flexibility and intuitiveness needed for real estate. Realvolve was designed specifically for the real estate business, which means that its intuitiveness cannot be matched. It is the best and it is what we use ourselves, which is why we recommend it to our members.
For more information on Realvolve go to: http://realvolve.com/
This video gives you a run-down of what Realvolve offers your business: https://youtu.be/BSOj5xF-_sI
For more information on Google Apps for your business go to: goo.gl/8Ta3O6