@serenesurface-- I think it depends on the company and how they manage the email system.
I do email companies and business when I have a question or problem. Some are very responsive and provide as much help through emails as they would through the phone. Others are not very responsive and either ignore the emails or give an insufficient reply. Sometimes I also get a response asking me to call them, which beats the purpose of using email in the first place.
I think email is a better line of communication between customers and companies. But it's only effective if the company uses it and manages it well.