Should emails be short or long?

As long as necessary, as short as possible. There's no universal right length. It udepends on your goal, audience, and content value. A flash sale notification should be brief. A detailed product launch might need more space. A founder's letter could be long if it's genuinely interesting.

The real question is: does every word earn its place? Long emails filled with valuable content outperform short emails with padding. Short emails that say nothing get deleted. Remove filler ruthlessly. If removing a sentence doesn't hurt the message, remove it.

Length should match reader investment. How much attention have you earned? New subscribers grant less than loyal customers. Promotional emails get less than newsletters they signed up for. Respect the implicit contract: don't demand more attention than you've earned the right to request.