1. Diversify your Content: If your entire email focuses on one product, service, or topic, you risk alienating all but the few people who will be interested. Unless you have segmented your database based on previous behavior, do not send an email on only 1 topic. I consistently find that the click through rate increases in proportion with varied content.

2. Don’t Stress about Spam Words: Many experts will tell you to avoid words like “free” or “sale”. In my opinion, ISPs tend to be moving away from content based spam filtering in favor of reputation based filtering. In other words, your sending IP address and from email are more important than whether or not your email contains certain words. Personally, I’ve used words like “free” in the subject line without any affect on delivery rates.

3. Make it Readable with Images Disabled: Always take into account the appearance of your email with images disabled. For email clients such as Outlook, this is now the default feature. Even popular web mails like Hotmail now disable images unless the sender is in the address book of the recipient. The best tactic to create readable emails with images block is use an alt description.

4. Create an Online Version: Always provide an online version of your email for users having trouble viewing images. I’ve calculated from emails I’ve sent in the past that around 5% of users will use this feature.

5. Remove Inactive Subscribers: Inactive subscribers are the most likely to get you in trouble by clicking the spam button. Consider automatically removing a subscriber that hasn’t opened an email in several months.

6. Proofreading: Always have every email proofread by at least 2 detail oriented people. There’s nothing more embarrassing than a typo in an email blast.

7. Monitor Replies: When you send out thousands of emails, you’re bound to get a few replies. Occasionally, you’ll get some good feedback from your subscribers. In addition, some people reply with unsubscribe requests.

8. Unsubscribe at Top: I know what you’re thinking, “At the TOP!?” Yes, at the top. Lazy unsubscribers have a tendency to click the spam button instead scrolling down to find the unsubscribe link. By placing the link at the top, you might increase your unsubscribe rate, but that’s better than an inflated spam complaint count.

9. Don’t Over or Under Mail: If you send too much, you’ll get deleted or marked as spam. Oddly enough, if you send once every 3 months you may have the same problem. Keep your brand top of mind for your customers by finding the perfect balance between over and under mailing.

10. Forward to Friend Feature: Many users automatically do this, but it doesn’t hurt to ask. First time potential customers can be very open to a company when it is introduced by a friend or colleague.

11. Subscribe Feature for Forwards: Make it easy for potential new subscribers to subscribe if they receive your email as a forward. Include somewhere in the body a subscribe link.

12. White List Reminder: If you want your subscribers to add you to their white list or address book, you need to ask. Sure, not everyone will add you. However, those who do are likely the people who care most about receiving your emails and, therefore, you have the most to lose if your emails get flagged as spam.

13. Single Click Unsubscribe: I generally recommend keeping the unsubscribe as simple as possible. However, you may want to confirm the action if you place your unsubscribe at the top of every email in case users click the link on accident.

14. Privacy Policy: Always place your privacy policy at the bottom of every email. Assure customers that you obtained their email address in a legitimate fashion, and you will not sell their personal info.

15. Don’t Rent Lists: Some may disagree on this, but I’ve never seen anything good come from a rented list. Don’t risk your sender reputation with emails from questionable sources. If you want to reach a new audience, consider a joint venture with another firm in a similar but non-competing industry.

16. Develop your Brand: Remember that your emails will slowly build your brand in the minds of your subscribers. Even if they never click-through and make a purchase, be sure to keep a consistent and accurate corporate image with your email content.

17. Call to Action: Each section must contain a specific call to action that avoids vague phrases like “click here.” You’ll be surprised how an effective call to action button or link can improve your click through rate.

18. Mix Freebies with Products: Too much selling can burn people out. Engage your subscribers with useful, free content. For example, if you sell home theater equipment, send out an article on the explaining the benefits of newer technologies. When you provide additional value to your customers with learning resources, they are sometimes even willing to pay more for your merchandise. In addition, strategies like this keep your brand top of mind.