Even after years of sending email, the way deliverability works remains a mystery to many marketers. If an email is sent and no one receives it, was it actually sent? In this two-part series and accompanying webinar, we will explore common misconceptions and provide tools to improve email deliverability. First, we’ll define deliverability and examine the email sender reputation score.


Deliverability vs. Delivered rate

Deliverability measures where (and if) your emails land in a customer’s inbox. If you have poor deliverability, your customers will not receive your email. And if customers do not receive your emails, they are not going to open and see your message.

You can have a high delivered rate and low deliverability. Delivered Rate measures the number/percentage of emails that do not receive a hard bounce (a message that is not delivered because the recipient's address is invalid, for example) or soft bounce (a message that is undelivered despite the email address being valid). However, the delivered rate does not take into account where the message is placed in the inbox. The message can end up in a spam folder or the promotional tab, so even if your subscriber receives the message, they may not see it.

Email deliverability is a crucial component of an email marketing strategy. Even if you design beautiful, personalized campaigns every week, your sender reputation determines whether or not your subscriber will receive your message. After all, 20% of emails never reach a subscriber’s inbox.


What is an email sender reputation score?

Internet Service Providers (ISP), like Comcast or AT&T, look at a myriad of data points and factors to determine whether or not they’re going to accept or reject a given email message. These data points also govern where the message is delivered--the prized inbox or the lowly spam folder. Think of this “reputation scoring” like credit scoring, where a whole bunch of your past spending and payment history is rolled up into an equation that governs whether or not a lender will trust you with a new loan or credit card. Much like different credit bureaus, ISPs use different scoring metrics from each other, so it’s possible to have a good reputation at one ISP but not another.


Calculate an email reputation score

  • Bounce rate is the percentage of visitors to a particular website who navigate away from the site after viewing only one page. The number of recipients who open, click, reply to, forward, and delete before opening an organization’s messages.

  • Unsubscribe rate is the percentage of recipients that ask you to remove them from these types of email messages. Of course, some number of recipients are going to unsubscribe after every send; this is expected. But an excessively high percentage of unsubscribing recipients is often an indicator that your mail is unwanted.

  • Whether or not you’ve sent mail to spam trap addresses. A spam trap is an email address that does not belong to a real person. ISPs, spam/security appliance vendors, and blacklists all maintain networks of spam trap addresses. Spam traps can identify organizations with irresponsible list building techniques. If you send email to spam traps, it’s an indication that you are not keeping your email list clean.


Protect your email sender reputation score

  • Use double-opt-in and reactivation campaigns. This way, you can make sure that an email address belongs to a real person and avoid spam traps.

  • Keep your email list clean! Purge your subscriber list regularly and remove invalid email addresses and non-responders.

  • Implement an IP warm-up plan. Do this by increasing campaign volume week over week.

  • Make your emails actionable! The more your customers click and interact with your email content, the higher your Email Sender Regulation score.

Did you know your file size also impacts deliverability? In our next post, we’ll discuss how email size can lead messages into the spam filter.  Want to increase your email deliverability and get your messages read? Watch our webinar with deliverability expert Al Iverson.