Actually, not at all.
For instance I was reviewing items in my Junk Mailbox and came across one allegedly from our insurance company, USAA. Looked VERY real, correct color scheme and font it appeared – BUT just didn’t smell right. So I clicked on the From line at the top and it showed the actual ‘person’ it was from:
Then I looked at the email and the fake-ness was confirmed == As you probably know ## don’t end in X’s -plus the name there is not the one USAA has for me.