tried it on a few projects in the past (domains & other areas) and it was a much higher click through rate using a professional email, also more engagement from their side - even use the domain you are selling as a last resort over Gmail, Hotmail etc etc
Edit
Also it works the other way - do not email people's personal addresses - always try and get their business email address.....should be self explanatory, but people think it is OK for some reason.
You need to come across as professional for people to take your seriously, especially when you are using email and not speaking to them.......