Getting started with email deliverability monitoring and performance metrics

You will learn

Learn what good email deliverability metrics look like by industry, and which strategies to use to help improve your email performance. In this guide, find out about the specific open and click rate, both for email campaign and flow messages, that you should strive for after depending on what vertical or industry you are in. Additionally, learn ways to help mitigate potential deliverability issues and how to continue to monitor these rates over time.

Before you begin

It’s important to understand the fundamentals of email deliverability and best practices to help you make your subscribers’ inboxes. Read our guide on email deliverability before you dive into evaluating your metrics. The metrics outlined in this guide are targets you should aim for after completing the warming process.

What to think about as you monitor deliverability

As you regularly review your campaign performance, it's a good idea to ask yourself the following questions to remain diligent regarding email deliverability issues:

• Spam complaint rates

• Any recent spikes? 
• If so, in what time frame? 
• What else changed recently? 
• Are these rates <0.01% per mailbox provider?

• Open rates (excluding MPP) over time

• Any recent drops? 
• If so, in what time frame? 
• What else changed recently? 
• What segments or lists does this impact? 
• Are these rates >33% for all industries (note that this could be higher for flow messages or during busier sending times of the year)?

• Unsubscribe rates

• Any recent spikes? 
• If so, in what time frame? 
• What else changed recently? 
• Are these rates under 0.3%? 

• Click rates

• Any recent drops? 
• If so, in what time frame? 
• What else changed recently? 
• What lists/campaigns does this impact? 
• Are these rates >1% for all industries (note that this could be higher for flow messages or during busier sending times of the year)?

• Bounce rates

• Any recent spikes? 
• If so, in what time frame? 
• What else changed recently? 
• Any specific mailbox provider (MBP) or ISP that is bouncing? 
• Are these rates <1%? In other words, this means for every 100 emails you send, 1 will be returned to you.
  
  

How to evaluate your email deliverability

There are a lot of numbers in your Klaviyo account, so you might wonder what good email deliverability looks like.

Opens, clicks, bounces, unsubscribes, and spam complaints come together to determine your overall deliverability performance and show how successfully you reach your subscribers’ inboxes.

Common “symptoms” that signal a deliverability issue include:

• Drop in opens
• Drop in clicks
• Spike in unsubscribe rates
• Spike in spam complaint rates
• Spike in bounce rates
• Drop in revenue/conversions 
• Reports of emails not being delivered
• Reports of emails landing in the spam folder

 These deliverability metrics are calculated in the following ways:

• Unique open rates
  The number of individuals opening your email divided by the number of emails delivered (as opposed to total opens, which measures the total number of times emails are opened).
  
  
• Unique click rates
  The number of individuals clicking a link in your email divided by the number of emails delivered.
  
  
• Bounce rates
  The number of bounced emails divided by the total number of emails sent.
  
  
• Unsubscribe rates
  The number of recipients who unsubscribe divided by the total number of emails delivered. These rates are measured on a per campaign basis, or you can view the list growth report for a particular list.
  
  
• Spam complaint rates
  The number of spam complaints about a particular email divided by the total number of emails delivered.

Deliverability metrics by industry

When looking at any of your deliverability rates, it's important to consider that these may differ slightly depending on your industry (i.e., some industries naturally see higher opens or clicks versus others). The charts below provide the averages that Klaviyo has gathered across our customer industries.

It’s worth noting that these are targets you should strive for after warming your infrastructure if necessary, and you should continue to use email marketing best practices and strive for further subscriber engagement. It’s also important to continue to monitor these values.

Opens and clicks benchmarks for email campaigns

The information below represents average email rates across Q3 2023. Note that Apple Mail Privacy Protection opens are included in the open rates presented.

Opens and clicks benchmarks for flows

The information below represents average flow rates across Q3 2023. Note that Apple Mail Privacy Protection opens are included in the open rates presented.

Negative Engagements

While open and click rates can vary across industries, you should aim to keep negative engagements as low as possible. Your negative engagement rates should remain in the healthy range: 

Bounce rates

High or rising bounce rates‌ are usually an indicator that you may have an issue with your list hygiene or your sender reputation. Regardless of industry, aim to get bounce rates as low as possible and aim to keep bounce rates within acceptable/healthy limits. Depending on your sending cadence, you should review your bounce rate averages every few sends or campaigns and try to improve them. Bounce rates can be an early indicator of larger issues, including those related to list hygiene, subscriber preferences, reputation with mailbox providers, etc.

In addition, low bounce rates go hand-in-hand with overall email marketing best practices. These practices include:

• Sending on a regular cadence to engaged subscribers and not emailing very old lists
• Cleaning your lists regularly
• Reviewing how you acquire your subscribers

Unsubscribe rates

Your unsubscribe rates represent the number of recipients who unsubscribed divided by the total number of emails delivered. In general, you should aim to be under a 0.3% unsubscribe rate per email campaign, regardless of industry.

While unsubscribes can be a normal part of email marketing and deliverability, excessive unsubscribe rates per campaign over time can cause mailbox providers to filter future campaigns away from the primary inbox. This may indicate there is a list hygiene issue that needs to be addressed in order to maintain good deliverability and reach subscribers.

However, you may have times where you are periodically encouraging subscribers to adjust their email preferences and confirm if they even want to receive your emails. In ‌these cases, you may expect to see unsubscribe rates potentially higher, and, thus, it’s key to monitor this rate in context.

It’s also important to consider how you are opting in your users and what consent they have given you to contact them. Consider if you are sending your subscribers the emails they expect to receive from your brand, what type you are sending, and when you are sending them. 

Spam complaint rates

When someone marks your emails as spam, this signifies to inbox providers that you are sending emails to people who do not wish to receive your mailings. These providers will then be more likely to send your emails directly to spam rather than an inbox in the future. 

Spam complaints are more dire than when someone unsubscribes from your marketing, and a rise in spam complaints should not be taken lightly.

If you have a high spam rate (over 0.05%), there are 5 key steps you can take:

1. Conduct spam tests
   Services like MailGenius will generally help you check whether your email is likely to end up in the spam folder by applying standard filters and scoring your email, as well as delivering your email to test seed list addresses in sample inboxes (e.g., Gmail, Yahoo, AOL, etc.). Although these services are not always 100% accurate, they can be helpful in identifying general issues or downward trends in your emails.
   
   
2. Identify “stale lists” or email addresses
   A "stale list" could originate from a competition or sweepstakes you ran, an event you held where you collected emails, or a list you haven’t emailed recently. You may also have issues with proper suppressions or segmentation in your sending habits, so performing a segment audit is another way to identify the problem.
   
   
3. Identify non-engaged subscribers
   Inbox providers will not only look at your sender reputation and content but also how often your subscribers are actually opening your emails. Although you may send to valid subscribers who originally signed up for your emails, subscribers that are rarely or never opening your emails can affect your reputation over time as these emails may eventually get shuffled into the spam folder. Therefore, it’s important to regularly review your lists, ask subscribers if they still want to engage with your brand via a re-engagement campaign, and clean out any subscribers who don’t want to hear from your brand or never responded regarding their preferences.
   
   
4. Review how you are acquiring subscribers
   Along with identifying problematic lists, it may be helpful to review how you are acquiring your lists to begin with. You will want to ensure that your forms adequately present your brand, what types of emails a subscriber should expect to receive, and how you will contact your subscribers. Learn more about implicit consent and best practices for using this when reaching out to subscribers.
   
   
5. Make sure your email renders with your unsubscribe link
   Inbox providers like Gmail can often clip or cut off emails that are too long, which could cause your unsubscribe links being cut off as well. With this in mind, it’s important to make sure that your unsubscribe link is accessible or possibly moved higher in your email so that subscribers can easily unsubscribe instead of just marking you as spam. Using the testing and preview function in Klaviyo and other services like Litmus can help you see a preview of your email in various inboxes to ensure your unsubscribe link is not cut off.
   
   

Use the following process to identify problematic lists and email addresses:

1. Create a segment specifying that someone meets the core condition you'd like to test. For example, they have a @gmail.com email address or are on the list that you created for a specific competition.
2. Add a second condition to the segment with the condition: has opened an email at least once within the last 12 months. 
3. Repeat this process for people not in the first group (i.e., use these same parameters to exclude subscribers who are in the first segment).
4. Compute open rates to see if the open rate for your test list is actually much lower than the open rate for your other lists.

Monitoring your deliverability in response to Apple iOS and MPP changes

Starting with the September 2021 release of iOS 15, macOS Monterey, iPadOS 15, and WatchOS 8, Apple changed how they handle email privacy. This will affect any email client checked via the Mail App on the Apple iPhone using iOS 15.

These changes could not only affect how you track subscriber engagement, but how you monitor your deliverability and reputation overall. We suggest following the steps below to ensure you are on top of your deliverability best practices.

Expand your engaged segment

For deliverability monitoring, it will be key to focus on other metrics besides opens to inform you if subscribers are actually engaged with your brand.

Email engagement data, like clicks and opens, will help you understand if your customers are actually interacting with your brand. If you are not using these metrics already, you will want to expand your engaged segment in Klaviyo to include them. It’s also important to note that non-email engagement data like purchases or onsite activity is also relevant, but since these do not impact how mailbox providers view your engagement, consider engaging with these subscribers through other means like social or SMS.

If you have any flows that trigger based solely on email opens, consider expanding that trigger definition to include other engagement criteria, like clicks or product views.

Remove unengaged segments

Once you have widened your engagement criteria, look at subscribers that may be unengaged.

With these changes to Apple Mail opens, we suggest creating an unengaged segment that includes at least clicks. As you continue to monitor your unengaged segment, you may want to expand this to include subscribers that were not active on site and did not make purchases.

Actively monitor and clean your lists

Besides simply monitoring your unengaged subscribers, regularly try to re-engage these people or even completely remove them from your lists. Regular list cleaning will ensure that you’re only contacting people who want to hear from you and help you maintain a strong reputation.

How to monitor key metrics over time

• Daily: Klaviyo Reporting
• Campaign segment reports
• Benchmarks
• Email provider trends
  
  
• Weekly: Google Postmaster Tools
• Domain reputation graph 
• IP reputation graph
• Spam complaints
  
  
• Weekly: Outlook SNDS (For accounts on dedicated IP only)
• IP reputation
• Spam trap hits

• Monthly: Seed list testing (e.g., Glockapps, Kickbox, Inbox Tracker, etc.)
• Which mailbox providers or ISPs are filtering us to spam?
• Monthly/Quarterly: Content testing (e.g., Litmus, Glockapps, etc.)

• Quarterly: Deliverability audit (Klaviyo or third-party consultant)

Deliverability hub

The Deliverability hub in Klaviyo is a centralized space that allows you to analyze and diagnose your email deliverability health at the account level.

To access the page, navigate to the Deliverability tab under Analytics.

On the Deliverability page, you’ll see account-level email deliverability reports that provide insight towards your performance with different inbox providers or email domains. There are reports for: 

• Positive engagement metrics
• Negative engagement metrics
• Email send volume

There is also a Bounce details page on the deliverability hub that provides information around why your sends are bouncing. If you are seeing issues with bounces, you can analyze this data to take corrective action and improve your overall email deliverability.

Campaign reporting

Use the following key metrics to evaluate your deliverability performance. These can be found by navigating to your Campaign trend report. This is your main report where you can monitor opens, clicks, bounces, and spam.

You can also create custom reports for campaigns, honing in on the metrics you care about most and viewing how they change over time. To do this, head to Custom Reports and create a new Campaign Performance Report. 

Campaign table

By default, your Email Campaigns page will show a table view as shown in the example below. 

You can also choose to expose the data for percentiles by toggling the option for Detailed View on the upper right side.

In these tables, note what your value is for various performance indicators (e.g., open rate, click rate, bounce rate, etc.). Compare your data with the recommendations in the table above and make changes where needed to boost your deliverability. Learn more about the metrics on the Campaigns Performance page and what they each mean.

Moreover, you should strive to have a status of Excellent or Good for each performance indicator. If your status is Poor or Fair, make efforts to improve these through new strategies. 

Campaign graph

On the Email Campaigns page, you can monitor how your campaigns perform over time, customizing the performance indicator, timeframe, and graph to focus on. 

Additionally, by hovering over any of these graphs for your campaign performance, you will see a breakdown of how your performance rating status (Excellent, Good, Fair, or Poor) was derived. Your rating will be a mix of Klaviyo best practices for benchmarks, peer groups, and overall industry statistics.

Campaign deliverability tab

The campaign deliverability tab in Klaviyo provides an overview of key deliverability performance metrics for your sends. You'll see the key deliverability metrics for your send along with a health status for each one. Additionally, you'll see your: 

• Email send volume breakdown
  Breakdown of where the majority of your emails are being sent (based on inbox provider, email domain, and country).
• Performance by inbox provider
  Breakdown of positive and negative engagements by inbox provider.
• Performance by email domain
  Breakdown of positive and negative engagements by email domain.
  
• Performance by country
  Breakdown of positive and negative engagements by country.
• Performance by email client
  Breakdown of positive and negative engagements by email client (i.e., desktop or mobile).
  

This can help you easily identify low-performing customer groups, so you can take action to protect your deliverability.

Benchmarks reporting

Another way to monitor your email deliverability performance is to analyze your deliverability-specific benchmarks. Klaviyo’s benchmarking tool allows you to evaluate and compare your data in relation to Klaviyo deliverability best practices, overall industry trends, and peer groups (i.e., companies similar to your own). Use this tool to take note of how your deliverability performance relates to others and Klaviyo guidance to determine where you can improve.

Part of how Klaviyo formulates peer group benchmarks is by using information on your industry and vertical. Your industry and vertical information is stored on the organization contact information page. It is important to keep this information up-to-date if it is not already. Learn how to update these organizational and vertical information settings.

Email performance benchmarks

Within the benchmarks section, there are 4 separate pages where you can analyze your data. By default, you’ll be directed to the Overview page. Select Email Campaigns from the main tab to hone in on your email marketing and deliverability performance.

Additional resources

• Understanding email deliverability
• Troubleshooting decreasing KPIs
• How to use benchmarks in Klaviyo