Email marketing remains a powerful and cost-effective marketing channel for engaging prospects and customers. In fact, B2B marketers find that email is the most effective way to distribute contentBut without giving proper attention to deliverability, sometimes even relevant, permission-based emails can get filtered out of subscribers’ inboxes.

Deliverability is the term used to classify the percentage of emails that actually make it into the intended recipients’ inboxes. According to Return Path’s latest Email Intelligence Report, 23% of emails never reach the inbox, on average. For marketers, each missed inbox is a missed opportunity to get the message across, and so every email matters.

Deliverability can be a result of many different factors—some which are beyond your control—but there are some practical steps that marketers can take to build a good reputation, improve their deliverability rate and optimize emails for more opens and clicks. Here are 8 tips that can help you improve your email marketing deliverability.

1. Send to contacts that expect to receive your emails

Email deliverability is partially determined by your Sender Score. Like a credit score, it represents your credibility as a sender. Companies with high sender scores take steps to assure that they are sending email to recipients that have elected to receive them and are opening and engaging with content.

A good rule of thumb for email marketing is to only send emails to people who want to- and expect to- receive your emails: customers, partners and other contacts who have opted in via web subscriptions, downloads or other form fills. You should aim to grow your lists organically, as purchased and rented lists can often lead to a negative impact on your reputation and less than stellar results.

Likewise, don’t take advantage of your subscribers. If they opted-in to receive a certain type of email from you (e.g. weekly blog update), don’t assume that they’d also like to be flooded with other messages such as promotional emails or content offers. If you would like to offer such promotional emails, inserting a call to action at the bottom of the emails that they’ve elected to receive is a good way to offer additional emails to those that want to receive them. It’s also helpful to use a subscription management option to give recipients the ability to opt out of certain types of emails, without having to opt out altogether.

2. Perform proper list maintenance

Equally important to your Sender Score is actively performing proper email list hygiene by weeding out invalid email addresses that hard bounce. Emails hard bounce when there is a permanent reason they cannot be delivered—A miskeyed email address or an email account that has been closed, for example. Keep your list completely free of hard bounces – invalid, mistyped and otherwise undeliverable email addresses that bounce when an email is sent to them. Internet service providers (ISPs) track what percentage of your emails bounce and a high percentage says that your lists are not clean, resulting in dings to your Sender Score.

Furthermore, failure to purge your list of invalid addresses can land you in a spam trap. Spam traps are inactive accounts set up by ESPs to catch spam. Not surprisingly, landing in a spam trap is a huge ding to your Sender Score. The general best practice is to regularly scrub your lists of invalid and inactive contacts. As with many things in marketing, quality is preferable to quantity. 

3. Focus on engaged subscribers

Subscriber engagement metrics are becoming a key factor in an ISP’s spam filtering determination process. One way to improve your engagement metric is to focus your email marketing efforts on contacts that have recently responded to your emails. Segment out your actively engaged recipients based on recent open and click activity during a particular time period, such as the past 30, 60 or 90 days and send your email only to that engaged segment. You can also try sending a separate, tailored email to your clean list of inactives asking whether or not they would like to remain on the list.

According to George Bilbrey, Return Path co-founder and president, “Senders that consistently reach the inbox tend to have higher read rates and more active subscribers. Senders whose mail is ignored – deleted without being read – are often the ones who struggle to get their messages delivered.” The point is, consistently sending emails to uninterested contacts (who are more likely to report your email as spam) that consistently ignore your emails, hurts your reputation metrics, and will ultimately hinder you from reaching people that are interested.

4. Monitor response rates

Staying on top of your email response rates is not just fundamental to understanding and optimizing your email marketing performance, but it also can play a role in improving your email deliverability as well. You’ll want to keep a close eye on your delivery rates, bounces (hard-bounces and soft-bounces), unsubscribes, complaints, opens and click-throughs, so you can spot any patterns or discrepancies and respond accordingly. If your results suddenly drop off, you’ll want to investigate to see what might be the cause and make adjustments. Consistently low response rates suggest that your content or list (or both) are bad and will lead to higher delete rates, which will affect your reputation and delivery. Optimizing your content for opens and clicks will improve your response rates as well.

5. Create relevant and engaging emails

While bad content alone won’t necessarily prevent your emails from being delivered, it will certainly lead to a high rate of unopens, unsubscribes, and spam complaints—all of which do impact future deliverability. It should go without saying, but your mission should be to send quality, relevant and helpful email content to your contacts. After all, the more relevant, personalized, and engaging your content is, the more successful your email marketing efforts will be.

6. Setup DKIM Authentication

Domain Keys Identified Mail (DKIM) is an authentication protocol used to verify the emails you send out. Used to identify spoofing, it’s like a digital signature that tells receiving email servers that your email is actually coming from you. It can help you establish and underscore the authenticity of your email, which will help improve delivery. With an increasing number of illegitimate senders attempting to spam, all ISPs are cracking down on illegitimate senders and enhancing their authentication protocols and so authentication is vital.

7. Play by the rules

The Federal CAN-SPAM law introduced a number of rules regarding the sending of commercial email. In a nutshell, it requires that all emails have a valid postal mailing address listed and a working unsubscribe link that promptly blocks the recipient from receiving future messages. It also requires that senders define the primary purpose of an email message. Making sure you’re in compliance with these and other CAN-SPAM rules is critical. Failing to do so will not only affect your sender reputation, but could result in fines.

Additionally, the General Data Protection Regulation (GDPR) went into effect this year. Although this regulation was aimed at protecting European citizens, there are implications for US-based businesses as well that effect email marketing. Depending on your level of contact with EU citizens, you might be required to obtain an opt-in twice on email subscription forms before adding subscribers to lists, as well as add a subscription center so that users can adjust their settings on

8. Choose a solid email marketing platform

As email deliverability continues to become more and more complex, it’s important to choose an email marketing or marketing automation vendor that has an established track record and the sophistication to help you navigate the ever-changing landscape. While much of deliverability rests on you the sender, the business processes and reputation of the email service provider you use also affect it. Solid email marketing platforms also have better tools for segmenting and cleaning your lists.

Email deliverability is all about working to ensure that your permission-based email is delivered to the intended recipient. And while achieving 100% deliverability might be a stretch, following these best practices can go a long way to helping you get closer to that goal. For more in-depth information on email deliverability, I recommend reading Act-On Software’s eBook: Best Practices in Email Deliverability.