Writing Advice: Mailing Lists / Newsletters

I've developed a HUGE pet peeve since becoming an author and it has to do with mailing lists. I have one. Most people like mailing lists, because they are targeted promotion to people who WANT to receive news about what you're selling. My pet peeve is when people do it wrong.

On more than one occasion, I've had an author drop me a group email newsletter sent from their mail client. Said email