My client runs a medical business. Is there a free online dashboard he can use in order to communicate with his coworkers with? Perhaps something with calendars.
I know bbedit used to have boards. But I am not sure if those forums are no longer in existence. I will have to investigate. How about a Google+ forum? Can Google+ be made to be private with only invited users.
My client uses GoDaddy for their hosting company. Perhaps they offer something.
If it’s medical business there is doctor-patient confidentiality to take into account. I would thread very carefully and make sure the service you pick is very secure to prevent leaking of confidential data.