I was able to set up gmail to send and receive using my business domain name. So not only do I have the option of sending mail as a
yourname@gmail.com, I can send as a
yourname@businessdomainthatiown.com. I just recently figured that out. I knew that I could point any mx record to whatever email i wanted, I just didnt know I could send as that as well.
I wonder if this would work for your purposes? If so, I can tell you what to look for in Gmail.