9 Email Statistics You Shouldn’t Ignore

Is Your Email Sending Ready For Prime Time?

Have you ever watched the game show, Jeopardy!? Contestants face a big board full of clues in random categories that pop-up without warning, and have five seconds to sort through a lifetime of knowledge to come up with the correct answers.  Sometimes email marketing can feel like the game of Jeopardy!, especially when rolling out a new email campaign. There is the potential for significant gains—you might even stumble onto a Daily Double!—but when the categories are unfamiliar, and there’s stuff you don’t know, it can be easy to get stressed out.

Now imagine you know the categories ahead of time. Today’s post is kind of like that. We’ve compiled nine vital email statistics – and a bonus cheat sheet! – that will help you make sense of your email delivery data.

1) Deferral Rate

Deferral Rate Screenshot

Let’s start with deferral rates for $1,000! (Yes, that’s a Jeopardy! joke.)

A deferral is a delivery attempt that failed because the ISP that the email is destined for essentially responded: “Sorry, try again later.” Deferred messages are retried later. (GreenArrow, by default, retries a message for two days.) The lower the deferral rate is, the faster and more efficiently your emails get delivered.

Deferrals are typically caused by reputation or rate-limiting problems with your email. They are the ISPs’ way of letting you know there’s a problem without rejecting all your emails right away. Deferrals also sometimes happen when an ISPs internal systems are overloaded. You’ll know the difference by looking at the deferral message. It will say something like “server too busy” or “resources unavailable.” 

Obviously, the lower the deferral rate, the better; we generally like to see it remain under 5%. Wondering what you can do to lower your deferral rate? Check out How ISP Rate Limiting Is Ruining Your Relationship for more details.

2) Throttle Rate

Your throttling rate tells you how much your email delivery was slowed down by your software.  For example, GreenArrow’s internal throttling settings limit the speed that emails are delivered to ISPs. A throttling rate of 0% means no slowdown.

Now you may be wondering why in the world anyone would want to slow down their email delivery intentionally. The answer is deliverability. To control spam and allocate their finite email server resources, ISPs defer your email if/when you try to send too fast. It’s best to work with those limits rather than against them. Throttling is a proactive way to prevent your delivery system from trying to push more mail through than the ISPs are ready to accept.

The lower the combined throttle and deferral rates are, the faster and more efficiently your emails get delivered. Thus, the more time-sensitive your emails are, the more important it is to maintain low deferral and throttle rates.

We like to see a throttle rate of 50% or lower.

3) Bounce Rate

Your bounce rate tells you what percentage of messages could not be delivered due to bounces. Messages can bounce for a wide range of reasons, including being sent to an invalid email address or due to deliverability issues. And unlike throttled and deferred messages, bounced messages are not retried.

The lower the bounce rate, the better. We generally like to see it remain under 2%, which is only possible if you’re keeping your email list clean. Some types of bounces should cause a subscriber to be deactivated, but others shouldn’t, so having a smart bounce processor (like the one GreenArrow offers) is huge. You can check out our blog, What Is a Bounce Processor, and Why Does It Matter? To learn more about the different kinds of bounces and what should be done with each one.

4) Open Rate

Open Rate Screenshot

The open rate is the percentage of subscribers that open, or “render” your email. It is one of the most critical and visible statistics.

There are two dangers of low open rates:

  1. If you are not getting Inbox delivery, a low open rate (and a lower response to your email offer) is showing you the cost of  spam filtering.
  2. If you are getting Inbox delivery, a low open rate can hurt your deliverability because it shows mailbox providers that your recipients don’t care to read what you are sending.

And here’s the catch. There is no direct way of measuring an “actual open” of an email, so the industry-standard method of measuring this is to embed a special image in the email and track when that image is downloaded/rendered. This is why the open rate is sometimes called the image render rate or the render rate.

So what drives your open rate? Two things:

  1. How well your emails are delivered to the Inbox
  2. When a recipient sees your email in their Inbox, how likely they are to open it.

The from name and subject line are the only parts of your email that are visible before it is opened, so those are critical to the open rate. Additionally, the subscriber’s recollection of the value of past emails and the strength of your brand play a huge role.

We like to see a 10% to 21% or higher open rate, depending on your industry.

5) Click-through Rate

Click Through Rate Screenshot

The click-through rate measures the percentage of recipients who click on links within the email.

Several things come into play to determine your click-through rate:

  1. What percentage of emails you send are delivered to the Inbox
  2. What percentage of Inbox-delivered emails are opened (In other words: how enticing is your from name, or your subject line, or brand)
  3. What percentage of opened emails get clicked (how well does your content invite clicks.)

If the goal of your email is to drive a response to your website, then measuring the click-through rate is critical.

We like to see a click-through rate of 0.5% to 3% or higher, depending on your industry.

6) Click to Open Rate

The click to open rate represents the ratio of unique clicks to unique opens. For example, if 100 subscribers load images (which tells us that they viewed the email) and 20 of them click on a link, then the click to open rate is 20/100 or 20%.

The click to open rate is a good way of measuring just how engaging and enticing your content is once it is viewed.

We like to see a click to open rate of 5% to 15% or higher, depending on the industry.

7) Spam Complaint Rate

The spam complaint rate is key to knowing how your email is being received. The rate is based on how many recipients are clicking on the “Spam” button—either because they don’t recognize your email or because they don’t want it anymore. Keeping this low is critical for email deliverability.

GreenArrow has this information because many (but not all!) mailbox providers offer a “feedback loop,” where they send you a notification when a user clicks on the “Spam” button. GreenArrow uses this notification to automatically deactivate the complaining subscriber and report the complaint in its stats.

There are two ways to measure the spam complaint rate. The first is overall for the campaign: how many recipients complained divided by how many emails were successfully sent.

Spam Complaint Rate Screenshot

We recommend keeping this below 0.1%.

The second method is to look at the complaint rate for each domain name:

Spam Complaint Rate By Domain

We recommend keeping this below 0.2%

But beware—a low spam complaint rate can sometimes indicate a problem. A low spam complaint rate indicates a great email program, but it can also be the result of poor deliverability. How? Simple: if your emails are delivered to the Spam folder, then your complaints will be lower because emails in the Spam folder can’t be complained about. For more information, check out The Most Misunderstood Statistic In Email Delivery for more details.

8) Unsubscribe Rate

Unsubscribe Rate Screenshot

Nothing lasts forever.  Summertime comes to an end; ice cream melts; kids grow up. And your valued subscribers sometimes unsubscribe from your email.

We like to see an unsubscribe rate of 0.05% to 0.3% or less, depending on your industry.

Comparing the unsubscribe rates between your campaigns can help you understand what your subscribers like to hear from you. We find that emails that deliver less value often have higher unsubscribe rates.

9) Weighted Inbox Rate

Weighted Inbox Rate Screenshot

Most emails only get read if they’re delivered to the Inbox, so keeping track of what is and isn’t landing in the Inbox has a lot of value. Not landing in the Inbox will depress all of your other statistics and the results that you want the email to generate.

This rate can be calculated by using GreenArrow Monitor to send samples of your email to test accounts at many ISPs. The percentage of messages to these test accounts that went to the Inbox averaged and weighted by the number of recipients in your campaign to each ISP, yields the weighted Inbox rate.

The stats also show the results for each mailbox provider with GreenArrow Monitor test accounts. This allows you to determine where the email delivery problems lie. For example:

Weighted Inbox Rate by Mailbox Provider

We like to see a weighted Inbox rate of 95% or higher.

Bonus: Target Rates Cheat Sheet (PDF)

Cheat Sheet--9 Target Rates for Your Next Email CampaignGiven that there have been so many numbers thrown around in this blog post, I thought it would be helpful to compile the target rates for each statistic. Many of these numbers vary by industry so these are meant to serve as guidelines or general benchmarks of where you should be.

And because we strive to make your work easier, we’ve put it all together into a handy cheat sheet PDF that you can download and have on hand for all your future campaigns. Enjoy!

Knowing the Answers is Only Half The Battle

Great! You have the cheat sheet, but what else do you need? Any Jeopardy! fan will tell you; it’s not just about the answers, it’s about asking the right questions as well.

What questions do you need to be asking your team when it comes to email marketing? What are your email statistics telling you, and how can you make the most of them? And of course, is it time to stop thinking about it and request a free GreenArrow demo?

FUN FACT: One of our team members, Tina, was recently a contestant on Jeopardy!. We always knew she was smart, but wow, some of those questions they asked blew us away. Great job, Tina!


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