support@domain, info@domain, purchasing@domain, sales@domain, etc

I can quickly imagine several situations in which one might speak to a public facing individual but still like to say "I was told by {sales rep} that {statement} was the case" or "{Employee} in support assured me this would be resolved in {timeperiod}" or "I had an excellent conversation with {employee} and want to ensure they'll be getting any commission due to them because they really convinced me more than your website"

See RFC 5322:

  From: "John Doe" <[email protected]>

Eh, I'm ambivalent. Letters in the mail have a From and people still sign them and some people even date them even if there's a post mark. At this point though it's more work for me to remove my signature. Plus my signature has my phone number.