How to tell whether your newsletter is working for the business now that open rates are unreliable
Open rates no longer tell you much. Here are the metrics that show whether your newsletter brings in customers and how to measure them with few resources.
If you measure your newsletter by its open rate, you are looking at a figure that no longer means what you think it does. To find out whether it is working for the business, look at useful clicks, replies, attributed conversions and list health. Opens remain a supporting signal, not the outcome.
Why can’t I trust the open rate any more?
Opens are measured with an invisible pixel that loads when someone opens the email. Since iOS 15 (September 2021), Apple has offered Mail Privacy Protection in its Mail app, which loads that content automatically even if the person never reads the message. The result: many recorded opens are not real reads.
Add to that other factors: email clients that block images, corporate filters that scan links and bots that “open” and even “click”. You don’t need to know the exact percentage on your list to draw the practical conclusion: the open rate is useful for spotting major problems, not for deciding whether the newsletter works.
So which metrics should I look at?
Choose just a few, and make sure they connect with something the business values. For an SME, these five are usually enough:
- Clicks on the main link: not total clicks, but the ones that lead to the action you care about (booking an appointment, viewing a product, downloading a guide).
- Replies: if people reply to the email, they are genuinely reading it. Hardly anyone measures this, yet it tells you a lot.
- Attributed conversions: enquiries, sales or bookings that come from the newsletter, measured in your web analytics.
- Unsubscribes and spam complaints per send: if they rise, the content or the frequency isn’t right.
- Net list growth: sign-ups minus unsubscribes and bounces. A shrinking list warns you before any other figure does.
A newsletter with few clicks that brings in two enquiries a month is worth more than one with lots of opens and no consequences.
How do I measure this without building a complex system?
You don’t need new tools. With your email platform and Google Analytics 4 (or whichever analytics you use), you can do it in an afternoon:
- Tag your links with UTM parameters (for example, utm_source=newsletter, utm_medium=email and utm_campaign with the send date). Many platforms do this automatically if you switch it on.
- Define a clear conversion on your website: a form submission, a booking or a purchase. Without this, all you will see is visits.
- Create a simple sheet for each send with the date, topic, clicks on the main link, replies, conversions and unsubscribes.
- Review monthly, not after every send: a single email tells you little; the trend over three or four months shows you which topics and formats work.
If you want to go further and bring your newsletter together with your other channels in a dashboard, that is exactly the kind of work we do in analytics and measurement.
What does deliverability have to do with all this?
A great deal. If your emails end up in spam, it doesn’t matter how good the content is. Since February 2024, Google has required bulk senders to Gmail accounts to authenticate their domain (SPF, DKIM and DMARC), offer one-click unsubscribe and keep their spam rate low, as set out in its email sender guidelines. Yahoo announced similar requirements around the same time.
Even if you don’t reach those volumes, meeting these requirements is good practice: ask whoever manages your domain to check the authentication, and remove contacts who haven’t clicked anything for months. A smaller, more active list usually has better inbox placement.
And the legal side
In Spain, sending commercial communications by email is regulated by Law 34/2002 on Information Society Services (LSSI), which in Article 21 requires, as a general rule, prior consent and a simple way to unsubscribe. Measuring properly starts with a list that has been built legitimately.
How do I improve a newsletter that isn’t delivering results?
When the numbers show little movement, one of these three things is usually the problem:
- There is no reason to click: the email summarises instead of inviting. A clear main link and a single goal per send help.
- The content is about you, not the reader: swap company news for answers to your customers’ real questions.
- The frequency isn’t sustainable: a carefully made monthly newsletter is better than a rushed weekly one.
Test one change at a time over two or three sends and compare it with your sheet. That way you will know what actually moved the needle.
Where to start this week
Open your last six sends and note down, for each one, the clicks on the main link, the replies and the unsubscribes. Tag your next send with UTMs and define a conversion on your website. In a month you will have a real basis for making decisions. If you want to rethink the design and content of your newsletter so it has a clear goal, tell us about your case through design and content.
Frequently asked questions
Should I stop looking at the open rate?
Not entirely. It is useful for spotting sudden drops, which can point to deliverability problems. But don't use it to decide whether the newsletter works: for that, look at clicks, replies and conversions.
How many subscribers do I need for a newsletter to be worthwhile?
There is no minimum figure. A small, well-segmented list can generate more enquiries than a large, cold one. What matters is that your subscribers are real customers or potential customers.
How often should I send the newsletter?
As often as you can sustain with quality. For many SMEs, once a month is enough. Keep an eye on unsubscribes and spam complaints: if they rise when you increase the frequency, go back.
What are UTM parameters and why do I need them?
They are tags added to the end of a link so that your web analytics knows where a visit came from. Without them, newsletter traffic gets mixed up with other channels and you can't attribute conversions to it.
Can I send the newsletter to contacts who gave me their card at a trade fair?
In Spain, the LSSI requires, as a general rule, prior consent for commercial communications by email, with some exceptions for customers with an existing relationship. If you have doubts about a specific case, check with a legal adviser before sending.