How To Improve Your Email Deliverability Rate

If you are already planning back-to-school and holiday campaigns, now is the time to ensure that your emails are not getting caught in spam or junk folders. 

Creating an effective email cadence is just the first step in building a cross-channel marketing strategy. But if your emails are going to junk folders or being flagged as spam by major Internet Services Providers (ISPs), chances are you have a deliverability problem that can impact your bottom line.

Email deliverability is the ability to deliver emails to subscribers’ inboxes. ISPs like Google, Yahoo!, and Hotmail use a variety of metrics to determine whether or not they will actually send your email to the inbox of the intended recipient. Protecting users’ inboxes is the top priority for any ISP.

Each ISP uses its own set of signals to evaluate your sender reputation and then determine if your email will be delivered to the recipient’s inbox. 

Many of these signals change dynamically based on the current stream of emails that ISPs receive. This means that an email that might be good today or suspicious tomorrow. Unfortunately, spammers are always trying to mimic and clone legitimate emails to fool these mechanisms. In fact, ISPs outright block over 95% of mail they receive as true SPAM/Phishing or malicious mail. Mail that actually gets delivered, especially to the inbox, is a very small part of what is received.

What is Sender Reputation? 

Your sender reputation is largely based on two main factors: the engagement levels of your audience and the quality of your lists. ISPs use sender reputation to determine how to treat your email streams.

Email service providers (ESP) like Sailthru by Marigold have helpful tools to view performance metrics like unique opens, total opens, and bounce rates. Metrics like low bounce rates and high open rates do indicate a healthy sending reputation — but they do not necessarily tell the whole story. 

ISPs on the other hand, have their own way of determining if you are a healthy sender. They have access to more details about users and their interaction with your emails. ISPs look at how long a recipient spends reading an email, if the viewer added you to their contacts, and if your email was deleted without being opened.

While you may not be able to control all the factors that imply a healthy sending reputation, these are a few things that contribute to a score:

  • User engagement
  • Invalid addresses (hard bounces)
  • User complaints
  • Spam trap hits
  • Drastic changes in send volume 

A healthy sender reputation is critical to reaching your recipients. During high volume moments like back-to-school or holiday season, an email will face even stricter filters and long delays due to the increase in volume ISPs are receiving. 

A drop in engagement can have a negative impact on your bottom line.

Assessing Your Deliverability Rate

Sailthru by Marigold makes it easy to keep tabs on your deliverability rate within your campaign dashboards. Open rates should be consistent across the top ISPs. If one is significantly lower than the rest, you may have an inboxing issue. Some of the most-used statistics include: 

  • % inbox – The percentage of your seeded messages delivered to the inbox
  • % bulk – The percentage of your seeded messages delivered to the bulk or junk folder
  • % missing – The percentage of your seeded messages blocked as spam 

Other indicators to use and monitor: 

  • Use Gmail’s Postmaster Tool. If your IP and/or domain reputation dips to the low or bad category, that is usually an indicator of a sender reputation issue at Gmail.
  • Keep an eye on soft bounce rates. If soft bounces are higher than the norm across any major ISPs, reach out to Sailthru. The ISP could be blocking your mail due to abusive metrics or a poor sender reputation. 

How Do I Know if I Have Deliverability Issues? 

Sailthru’s team of experts recommends a continuous view into five main variables: 

  • Hard bounce rates- Anything above 0.5% should be reviewed. 
  • Complaint rates- High complaint rates indicate that users do not like what you are sending – either the content or the frequency. 
  • Fluctuations in overall open rates-Low open rates can show poorer engagement and play an important role in your sender reputation score.
  • Opt-out rates- If opt-out rates rise, take a look at what you are doing and adjust. You don’t want to sacrifice your loyal year-round list for seasonal batch and blast campaigns.
  • Increase in sign-ups that are potential BOTs- Any unusual spike in sign-ups should be investigated immediately. We recommend Google reCAPTCHA to eliminate the risk of a BOT attack.

How Can I Improve My Deliverability Rates? 

Keeping deliverability rates high comes down to the integrity of your email list and the quality of your content. The basic tenets are: 

-Do not mail to older lists that you have not been consistently mailing to.

-If you plan to re-engage with some of your less engaged users, make sure you reintroduce them strategically, over time. It’s important that you don’t send to your entire list of less or unengaged users – rather, they should be gradually re-engaged ahead of a large-scale campaign.

-Be cautious of new acquisition sources. Test them prior to a campaign launch and be sure they are not generating poor quality metrics such as complaints or hard bounces. 

-Make your sign-up and opt-out pages easy to navigate.

-Be careful changing your sending cadence. ISPs will penalize you for an inconsistent spike in send volume, so increases in cadence should happen slowly. Offer preferences to allow users to opt down from increased marketing.

-Do not change your sending domain.

Want to learn more? Download this case study showcasing how Market Briefs, a daily newsletter for investors, worked with the experts at Campaign Monitor by Marigold to maintain high deliverability rates while tripling their readership in less than a year. 

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