I routinely write e-mails without any kind of fluff, generally it's:
Yourname,
Lorem ipsum. Blahblahblah. Blhablahblah. Blahblahblah.
Mike
Sent from my iPhone <--- if applicable (part of its signature)
I view myself as plenty professional. I get straight to the point. If my e-mail contains any decorative text, it's because I meant it.
Go Google for e-mails sent by Steve Jobs. They're even briefer.
Well no offense, but I imagine nobody would expect much more than that from a trinket seller. Additionally, the source of the complaints is being rude, or just one word replies, which are both unprofessional. Your emails are neither, and I for one appreciate brevity.