if i send a private letter with a return address of my office, i am not representing the company, even though the company name appears on the envelope. An email domain is no different than a street address.
I'm not sure. The return address is printed on the back of an envelope, whereas the sender's email address is prominently displayed at the top of everything you send.
It's a subtle difference, but IMO a relevant one. I think it's closer to writing a letter on the company's stationery, letterhead and all. Particulary since, in my experience, company email accounts normally add a signature with company's contact information and the sender's position in it.
