How to Improve Email Marketing Open Rates

Internet Marketing — specially email marketing — is an essential part of any successful marketing strategy. As such, I’d like to share some essential tips on how to improve email marketing open rates (while not getting flagged as spam).

First and foremost, for email marketing to be successful, your emails have to make it passed spam filters. Considering that email spam is running rampant and incorrect spam filter classification can affect open and click-through rates by as much as 20-30%, getting your emails seen is an ongoing battle.

Here are some tips to help increase delivery and open rates of your email marketing messages.

1. Get Permission

If you’re sending email marketing messages to people without getting their permission, then STOP.

That’s called spam.

People hate spam.

And it doesn’t matter what “unsubscribe” information you include or if it’s a “one-time mailing”, it’s still spam.

If you want to send marketing emails to someone, you should use a process called “confirmed opt-in” (also known as “verified opt-in” or “double opt-in”). This is the legitimate and professional process for adding people to your email marketing list.

A confirmed opt-in process is pretty simple.

  1. Someone voluntarily requests (subscribes) to be added to your email list by giving you their email address.
  2. Your email list management system sends the person an email asking them to confirm that they actually made the request.
  3. The person must then click a unique link in the email to confirm the subscription. This verifies they are the same person who made the original request. If they don’t click the link, they’re not added to the list.

2. Get Valid Subscriber Email Addresses

When requesting website visitors to subscribe to your email newsletter, ask them for their “primary” or “business” email address. This will help increase the chances of getting a valid email address because free email addresses from Gmail, Yahoo!, Hotmail, etc. tend to be “throw away” accounts and typically have a shorter lifetime. This also means you’ll see a lower bounce rate.

3. Request Subscribers to Provide their Name

There’s both positive and negative sides to requesting subscribers to provide their name.

  • Higher Quality List
    • Subscribers who give you their name are typically more serious about subscribing, This means you’re more likely to get real people subscribing who are also using a real (valid) email address.
    • A subscriber list (with names) can give you a more responsive list (that’s a huge benefit).
    • Note: Just because someone gives you their name doesn’t mean it’s their real name
  • Lower Opt-in Rate
    • Privacy. Understandably, people don’t like to give out their name to someone they don’t know. So if a ‘name’ is required, some people will simply not subscribe.
    • Asking a subscriber for their name means they need to fill out another form field. And, as we know, the more information you request, the lower the opt-in rate.

4. Maintain Your Email List

Like any good rose garden, you need to keep the bushes pruned. This means you want to trim undeliverable addresses.

If you’re using a paid service to mange your email list, they’ll most likely have a system in place to automatically remove subscribers whose emails are bounced back as undeliverable.

If you manage your list internally, addresses that bounces with a permanent error 2-3 times in a 30-day period should be removed. ISP’s track what percentage of your newsletters bounce and will block them if you attempt to continually deliver messages to closed subscriber mailboxes.

I also highly recommend trimming unresponsive subscribers from your list. There are many reasons for this which I’ll cover at a later time.

5. Use Acceptable Email Message Format

HTML email messages allow for better text formatting, multiple columns, inclusion of images, brand recognition, etc. And although HTML formatted messages are growing in popularity and widely supported by most email software, most email spam is also HTML formatted. This makes differentiating between requested email and spam email difficult. A study by AWeber shows that plain text messages are undeliverable 1.15% of the time and HTML only messages were undeliverable 2.3%. So if you’re going to send HTML emails, it’s important to send an alternative plain text message too.

Many ISP’s filter emails based on the content that appears within the message. As such, tips 6-12 will help decrease the chance of an ISP flagging your email message as SPAM.

6. Write a Powerful Email Subject Line

A strong and enticing email subject line is crucial to increasing email open rate. And using words like “Free” or “Buy” in the subject line are automatically suspect and not only increase your email spam score, but keep people from opening the email. Also, using ALL CAPS in your subject line is a big red flag too.

7. Avoid Spam Words & Phrases

Choose your language carefully when crafting messages. Avoid hot button topics often found in spam such as medication, mortgages, making money, and pornography. If you do need to use words that might be filtered, don’t attempt to obfuscate words with extra characters or odd spelling, you’ll just make your messages appear more spam like.

For more information, you can download this Email Spam Filter Triggers PDF.

8. Use Images Sparingly

When using images in your email marketing, if at all, make sure they’re adding to the sale message. Rule of thumb, if it’s not adding value to the message, delete it.

Avoid email messages that are created with images only. Commonly used open rate tracking technology use images to calculate opens. You may choose to disable open rate tracking to avoid being filtered based on image content.

9. Don’t Include Attachments

With viruses spreading through the usage of malicious email attachments, many users are wary of attached documents. It’s often better to link to files via a website URL to reduce recipient concerns and reduce the overall message size.

10. Email Message Links

A common mistake most new email marketers makes is to create a link within their email message that uses a website URL as the anchor text.

This will increase your spam score.
<a href=""></a>

This won’t.
<a href="">go to our website</a>

11. Website URLs

Please research potential advertisers before placing ads or links to them in your newsletter. If they’ve used their website URL to send spam, just having their URL in your newsletter could cause the entire message to be filtered, blocked, and marked as spam.

12. Adhere to CAN-SPAM Compliance

The Federal CAN-SPAM law introduced a number of rules regarding the delivery of email. It’s important you have your legal counsel review your practices and ensure you’re in compliance. The two most important rules include having a valid postal mail address listed in all commercial messages and a working unsubscribe link that is promptly honored to remove the subscriber from future messages.

CAN-SPAM Compliance Resources:

13. Increase Your Email Practices Reputation

Reputation services are often used by large ISP’s as a way to vet email senders regarding their email practices and policies. Businesses listed with these services are then given less stringent filtering or no filtering at all. Here are two reputation services: ISIPP and ReturnPath.

14. Relationships & Whitelisting

Contact with major ISP’s and email providers is essential to letting them know about your requested subscriber email. Many large providers such as Yahoo! have specific whitelisting programs and postmaster website areas to ensure your email is delivered — as long as you meet their policies and procedures in handling your opt-in list. Again, if you’re using a paid service, they’ll handle this on their end as the email messages are sent from their servers.

Email deliverability is about ensuring requested emails are delivered to the intended recipient. While no single tip will enable you to get 100% of your emails delivered, used together, they can help you reach that goal.

If you have any questions, just drop a comment below.

Here’s to your email marketing success!

Please post your thoughts and comments below. Thanks!


  1. chaduvae


    Thank You for your suggetions posted, it was really helpfull.
    We are going to start email marketing using Oracle siebel application, with OPT-IN and OPT-OUT options available.
    We will be sending news letters to the customers twice in a month.
    Do we need to address the same with ISP’s, If not what are necessary setups required on domain servers to ensure that our emails will not be blocked.

    We will be targeting 500 K plus customers.
    We want to do this Inhouse and no to 3rd party.

    Can you please assist on this.

    Thank You,

  2. kristofcreative

    @chaduvae Thank for your comment and question. One of the biggest mistakes businesses make when using an in-house system is sending emails in bulk — emailing their entire list at one time. Doing that will get you blocked and added to a spam list faster than anything.

    Ideally, you’ll want to send emails in small, staggered groups. My recommendation is to talk with your ISP before setting up your system. They can give you information about what activities they consider to be “spam” and suggestions for avoiding it.