RECEIVING EMAIL THROUGH COMCAST using Iphone 4S

As of ten days ago my iphone 4s is NOT receiving email.  I assume I am also not sending email successfully as well as nothing has been responded to. I own a small legal business that requires daily communication with lawyers.  I am a mediator and arbitrator, and have already missed several appointments and information of where arbitrations are to be held.  THIS CANNOT GO ON ANY LONGER WITHOUT MY GOING TO ANOTHER SERVER.  Comcast has been awful in general.  They do not respond to concerns in a timely fashion, and basically lie.