I know of a few instances of people resigning by email. Two weeks ago, one project manager and one engineer quit by email from my parents' company on the same d

I know of a few instances of people resigning by email. Two weeks ago, one project manager and one engineer quit by email from my parents' company on the same day. In one instance, I started working as a replacement for the engineer the day after. It's not inconceivable to me that a CEO would take that email as formal notice, or that they might find a replacement within 6 weeks.