This document provides guidance on using email marketing for professional marketers. It recommends segmenting lists by target markets like existing customers, new customers from rented lists, and lost opportunities. The email should include an interesting subject line to spark opens, and offer in the copy to drive clicks and conversions. Testing the email and split testing the subject line is also advised. Metrics like opens, clicks, and conversions should be measured, and emails should be sent every 10-15 days to remain relevant without annoying recipients.