Email Marketing Services
Effective Email Deliverability Best Practices


With email messaging, you’re essentially pleasing two audiences: your human subscribers and sensitive spam filters. Incorporating cutting-edge best practices into your approach can help satisfy both and allow you to focus on what really matters: engaging your email audience. Spam filters “rank” email by a number of criteria – if the email fails to abide by best practices, it runs the risk of not only being sent to an individual subscriber’s junk folder, but it also runs the larger risk of getting the original sender’s IP black-listed by an entire email client. Following are our best practices for avoiding the dreaded junk folder and the “delete” button guillotine:

1. Avoid using “trigger” words.

Some of these are obvious, like “Free,” “Save,” “$,” or “Discount,” but some of them are less obvious, like “dear,” “click here,” and “distribution.”

Solution: We run outbound emails through multiple tools to catch even the most innocuous uses of what seem like normal, everyday words.

Tip: Including the current date in the body (or subject line) of the email increases credibility and helps mark your email as non-spam.

2. AVOID USING ALL CAPS AND EXCESSIVE EXCLAMATION POINTS!!!!

Besides looking like you’re shouting, it can also flag your email as spam. Solution: Avoid using all caps, and excessive exclamation points.

3. Avoid using too many images, Flash, JavaScript and ActiveX.

Imagery can be a very powerful messaging mechanism, but in email, use them in moderation. Spam filters will flag email with a low text/image ratio. This is because actual spammers use one GIANT image to avoid using “trigger” words (see #1), and as a result, most image-based email correspondence is flagged. (Look in your spam filter and count the number of image-only emails, you may be surprised.)

Solution: A majority of your email should be text (the most-trusted type of email is a personal letter between two people – follow suite with your email newsletter). Use images sparingly, and wisely – this is also easier on the human eye.

4. Include a CAN-SPAM compliant footer.

Emails without unsubscribe links and physical mailing addresses reek of spam, and tarnish credibility (to both spam filters and human recipients).

Solution: Include both an unsubscribe link, a physical mailing address and a link to your privacy policy, but be careful of your wording and don’t sound too “official” with phrases such as “Stop Further Distribution” and other overly-formal language. Make it conversational and both the spam filters and your subscribers will appreciate it.

5. Keep your list squeaky clean.

When someone unsubscribes, they are doing you a favor. Don’t fool yourself into thinking your next issue will change their mind. And pay attention to your email bounce rate: Sending to email addresses that have bounced repeatedly will result in a blacklisted IP address – and then even your “good” subscribers won’t be hearing from you.

Solution: If a reader was kind enough to unsubscribe in the first place (as opposed to simply marking you as spam) then honor their request and remove them from the list. Plus, it’s about quality, not quantity. A list of 10,000 active subscribers is worth much more than a passive list of 100,000.

6. Don’t get too big for your britches.

Large email files are slow, bulky and suspicious (think of a bear in a bank wearing a ski mask – or don’t). Attaching PDFs, excess images or running a message too long can all be triggers for the spam filter.

Solution: Keep the file size of your email between 20 and 40 kb. It’s not much, so make it count. A small size typically coincides with the recipient’s attention span, so don’t waste opportunity with bulky graphics and extraneous files.

7. Are you sure? Are you sure you’re sure?

Sometimes site visitors will unknowingly sign up for your email newsletter and later call you a spammer. Sometimes spammers will knowingly sign up for your email newsletter for no apparent reason (the Internet can be a strange place).

Sometimes site visitors will knowingly sign up for your email newsletter and wonder why they never received it (they spelled their email address wrong, it happens!).

Solution: Use a double opt-in confirmation process. As soon as a site visitor enters their email address, send them a “Confirmation” email to make sure it’s valid – and to make sure they’re truly interested in your offer.

8. Ask to be whitelisted.

Even the most willing subscriber can sometimes miss out on your email if their email provider does the thinking for them. In other words – just because someone signed up for your email doesn’t mean it’ll get through, due to overactive spam filters.

Solution: Explicitly ask your subscribers to “whitelist” your email address – or add you to their address book. If they were willing to sign up to receive your newsletter, chances are, they’re willing to spend 30 seconds to make sure it gets through. (We can provide simple instructions for all major email providers.)

9. Address the subscriber, one at a time.

Some email programs will automatically filter out any inbound mail without the recipient’s email address in the “To:” field. And most humans don’t like to be addressed in impersonal ways (does anyone ever turn around when you yell “Hey!” in public?) And if you’ve got thousands (or more) emails to send, don’t send them all at once – this is a giant red flag if you have multiple subscribers sharing the same ISP (which you will).

Solution: Ensure that you aren’t using the CC or BCC field to address your recipients, and make sure you’re using a program that correctly places each individual’s email in the “To:” field.
And send your email in batches, or at a reduced rate so that ISPs don’t view your correspondence as a flood of emails, often the dark work of virus-makers and spammers.

10. Timing is everything.

You may have the greatest email newsletter known to man, but if you send it at the wrong time, you run the risk of man (or woman) not even knowing about it.

Solution: Current research indicates that Tuesday and Wednesday between 2pm-3pm (local time based on the recipient) is ideal for email distribution.

Sorry bosses, most email newsletters are checked at work, right after lunch (when general malaise begins to set in). Leverage this to your advantage and send your email when your target audience is most susceptible to reading it.

11. Pay attention to your subject line.

Your email newsletter may have something for everyone, but no one will open it up to find out if you try to jam it all in the subject line. Most email programs will display 60 characters or less (including spaces).

Solution: Keep it short, sweet, relevant and enticing. The goal here is to get them to open it – your enticing content is what will get them to click on to your site.

12. Design for the preview pane.

Your email subscribers attention span is a limited time offer. 52% of email readers view their email exclusively in their email program’s preview pane (according to ClickZ research).

Solution: Don’t design emails as wide as a webpage (or your monitor, for that matter). Max out at about 600 pixels wide so that key content is available in the preview pane. Left-align your company logo and make sure your important content (or teasers to it) are visible, too. And keep your call-to-action above the fold.

13. Offer both text and HTML-based email.

Unlike Flex-Fit Hats, email messages are not a one-size-fits all solution. And believe it or not, some people still browse the Internet in Linux (yes, a text-based browser). Solution: Offer both a text-based and HTML version of your email. Aside from catering to different types of email subscribers, having both versions is also a hallmark of legitimacy in the electronic eyes of ISPs.

14. Assume images will not display.

So your Marketing Manager has this awesome idea to base your upcoming membership-drive campaign off of the artwork on a famous Beatles album. It scores points for nostalgia and delivers your message perfectly. But all your email subscribers see is a tiny red X.

Solution: Images, aside from being a deliverability nightmare, can also hide your message from subscribers. Don’t place important content into images and use alt text so that those generic red X’s never display.

15. Test in multiple email programs.

Not everyone uses the email program you do. What looks good in Gmail, may be a distorted mess in Hotmail – and might not even show up in Outlook.

Solution: Learn what programs your subscribers are using and make sure your email shows up correctly in each one. Test in every email program you can find, and test with multiple spam filter settings. Email messages will display differently depending on the program, so make sure your email is universally optimized.

16. Avoid temptation for innovation, in some cases.

Maybe you created an award-winning email graphic that your co-workers (and maybe even subscribers) are oohing and ahhing over. Too bad they don’t know they are supposed to click on it to learn more about your offer.

Solution: Research indicates that more web users respond to links at a higher rate when they are bold, blue text links. Stick with what works until you have reason to do otherwise.

17. Consistency is key.

Think of the last cell phone you got. Chances are, there were some buttons on it that you weren’t familiar with and some functionality that came with a learning curve. You didn’t mean (because of the sheer novelty) and you spent a few hours tinkering with it and getting used to it. This is the exact opposite of how people read email and web sites. No one wants to spend time learning your new set of navigations on a weekly basis – no matter how innovative and “2.0” you might think it is.

Solution: Keep it simple and keep design consistent by using the same template for your newsletter. Design changes should be iterative for both branding, usability and sanity’s sake.

18. Don’t fatigue your list.

Everyone has that funny friend who can make them laugh at the drop of a hat. And most people, after a while, just wish they’d give it a rest. Don’t give your email subscribers too much of a good thing – or they might experience stimulus overload.

Solution: If your email is weekly, keep it weekly. Don’t send more frequent updates than what your readers have signed up for and don’t assume that they like you so much that they’ll listen to EVERYTHING you say. No one is that popular. Not even your funny friend.

19. Analyze, Rinse and Repeat.

What worked a year ago, might not work next year (you can thank spammers for that).

Solution: Measure open rates, bounce rates, forwarding rates and opt-outs to get a firm grasp on what is working and what doesn’t. Monitoring subject lines, analyzing subscriber feedback and keeping your list active (i.e. making sure subscribers are still reading) can keep your list healthy, your messaging on-point and most importantly, your subscribers happy.

20. Add domainkey & SPF for your sending domain.

Domainkeys & SPF will make lot of difference to the deliverability of the campaign. Together it will make sure that yahoo, gmail identify the mail coming from a valid source.

21. Warm up IPs and increase load gradually

It is recommended that when a fresh domain is setup with New IPs, the sender should not start blasting millions of mails from day one. To start with only few thousand mails should be sent and the load should be gradually increased.