Know your spam rules. A lot of innocent people send spam because they didn't know any better. Read up on the CAN-SPAM act to avoid any trouble. Put simply, you're allowed to send bulk email only to people who specifically asked to be on your mailing list. If you collected email addresses for a lunch giveaway or an event invitation, then you don't have permission to send marketing emails unless you made that clear at signup. Include an obvious unsubscribe link in every email, and don't forget to remind subscribers how they got on your list in the first place.
Think as well about the kinds of metrics you're evaluating. You probably know that interaction with email campaigns is measured through open and click-through rates. While it's meaningful to review email response in this way, if this is all you measure, you're missing the bigger picture of the value of email to your company and its customers. These rich metrics in the email are great. However, there is a distinction must be made between:
Alternatively, at least, an eye-catching design. It’s worth letting a proper designer have a go at prettifying your emails. Customers are often opening emails on the go, so you need to work hard to grab their attention. Making your emails nice to look at is a brilliant way to hold their eye. Netflix put time and effort into making their emails stand out, personally and visually – and it pays off for them!