Understanding Email Marketing Metrics

Before launching an email marketing campaign, it is essential to understand your goals to know if your campaign is successful. Monitoring and analysing your email marketing performance is the best way to get to know your subscribers and discover what works for your business. Monitoring performance should be part of your email marketing strategy from the start.

Creating a measurement plan

  1. Set goals and objectives. Performance tracking must align with business goals and objectives. Before you start, set goals for your email campaigns by which you can measure progress.
  2. Create a monitoring schedule. Make a regular appointment in your diary to assess your performance. This could be weekly, monthly, or campaign-by-campaign. Comparing progress against benchmarks and past performance makes it easy to spot patterns. These can then be recorded against a specific email campaign, customer segment, product type, or external factors.
  3. Analyse performance. Analysis can uncover the type of content engaging your subscribers by analysing the links or imagery that have driven the most clicks. By analysing your audience’s behaviour, you can learn more about them, for example, their interests the content that is effective in driving action and engagement.

Email Metrics

Email metrics that help you understand how your campaigns perform e.g. open rate, click-through rate and conversion rate. Your email marketing platform (e.g. Mailchimp) will provide these at the account and campaign level, where they can be compared over time.

List size and growth

The more email addresses collected from customers or captured from website visitors, the more extensive your email database and, to grow sales, the more potential customers you can reach. Your email service provider should enable you to monitor this vital metric to see how many new subscribers are added weekly or monthly.

There is a natural decline of your email marketing list of about 22.2% yearly. This means paying attention to growing your subscriber list and keeping it healthy is important.

Open rates

The open rate is the percentage of recipients who opened the emails they received. The average rate varies by sector but is around 15-25% (Source: Campaign Monitor[1]). The following factors influence the rate:

  • Subject line. The first things your recipients will see when they receive an email are the subject line, preheader text, and sender’s name. It must be compelling.
  • Preview text. Most email clients show preheader text next to the subject line. With most email service providers, you can edit the preheader text to control the preview content readers see.
  • Deliver relevant content. If your open rate is below average, you may deliver the wrong content to people.

Click-Through-Rate (CTR)

The click-through rate measures how many opened emails received at least one click-through to the target website. The average click-through rate is 2-3% (source: Campaign Monitor). This should be higher than your average website conversion rate as the email recipients have opted to see your content (e.g. past website customers).

CTR is a measure of how engaging your email content is. The email content, including images and calls to action, plays a significant performance role. The content is underperforming if your open rate is reasonable, but your CTR is low. A/B testing can be used to optimise the click-through rate.

Factor affecting click-through rate:

  • Clarity of the messaging
  • Offer in the email
  • Calls to action


Email deliverability refers to the proportion of emails that end up in the recipient’s inbox instead of bouncing or being classified as spam. When mailbox providers receive an email, they will run reputation checks to decide whether the message is SPAM. They make this decision by analysing the historical performance of the sending email address, the domain and the email’s content.

Factors considered will include:

  • The server’s reputation or IP address used to dispatch the email.
  • Domain reputation of links in the content.
  • Email bounce rates.
  • Spam complaint rates for the sender, domain and server.

To keep email deliverability high, it is essential to have a good sender reputation. Achieve this by keeping your list up to date. This involves:

  • Removing old emails. If an email has not interacted well in a long time, consider removing it. Also, remove any emails that bounce.
  • Opted-in subscribers only. Only send emails to subscribers who have given specific contact permission.
  • Quality content. Avoid the use of spammy titles, e.g. GET RICH QUICK.
  • Unsubscribe option. Always include a clear unsubscribe option.

Be careful! Many email service providers consider a 0.1% complaint rate the maximum acceptable threshold.

Conversion rate

After someone has clicked a link on your email, the next goal is to get them to take the action your email has asked them to take. For example, if you send an email offering your audience the chance to buy a discounted product, you will consider anyone who purchases to be a conversion. Factors affecting conversion rate:

  • Intent of the clicks
  • Quality of landing page

Bounce Rate

Bounce rate is the percentage of emails that could not be delivered to the recipient’s inbox. There are two kinds of bounces: ‘hard’ and ‘soft’.

  • Soft bounces. These result from a temporary problem with a valid email address, for example a full inbox or a problem with the recipient’s server. The server may hold these emails for delivery once the problem is resolved, or you can resend the message.
  • Hard bounces These are caused by invalid, closed, or non-existent email address. These emails will never be successfully delivered.

Your bounce rate should be low, as you should remove emails that bounce hard from your list. While a bounce rate does not effect your other metrics, you should still look at it to make sure there are no deep issues with your emails.


The purpose of most email marketing is to drive sales. If email marketing works well for your business, a reasonable goal is 20% of your sales coming from this channel.

Unsubscribe rate

The unsubscribe rate is when people opt not to receive your emails. Although unsubscribes are inevitable, assessing the unsubscribe metric gives you a sense of whether you send engaging content to your audience. Factors affecting unsubscribe rate and spam rate:

  • Sending frequency
  • Relevance of content
  • Segmentation

Spam Rate

Spam rate measures the rate at which contacts mark your emails as spam. A high spam score shows that your audience values what you send them. A high spam also indicates to the email service provider that you are not a reputable sender, so your deliverability will suffer.


While the performance of email marketing is individual to each business, an eCommerce business whose email marketing is going well might look like this:

  • 20% open rate. This indicates that you send relevant emails with interesting subject lines to the right people
  • 5% click-through rate. This suggests that the content and offers in your emails are compelling enough to click on.
  • 2-5% conversion rate. This indicated that your offer is attractive and users are find the content of your landing pages relevant.
  • 20% of website revenue from email marketing. Email marketing converts new customers and upsells enough to existing customers to justify further investment.

Mailchimp have compiled a list of metrics by industry which can be found here:


[1] https://www.campaignmonitor.com/resources/guides/email-marketing-benchmarks



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