Case Study: Increasing This Brand’s Email Deliverability Score by 622% in 90 Days

A health and wellness brand, specialising in personalised supplements, approached Swanky looking for email marketing to support conversion. Over the following three months we worked to migrate the brand’s email channels from HubSpot to Klaviyo, while simultaneously improving its email deliverability and engagement metrics.

In this case study we’ll share the strategies we executed, how we leveraged data to inform these strategies, and the final results of our engagement. In particular, we’ll look at how we improved our client’s deliverability score by 622% in 90 days.

What is a deliverability score?

Before moving into the work we completed, let’s establish what deliverability is and why it’s important.

Email deliverability is a metric that indicates how likely your emails are to successfully reach recipients’ inboxes rather than being filtered to spam folders or rejected entirely. This is influenced by four key points:

1. Who you send to and how they engage with your emails: This includes monitoring recipient engagement through opens, clicks, and other interactions.
2. Your sending habits: In other words, the frequency and volume of your emailing.
3. Email content: Inbox providers use spam filters to analyse your content, including images, links, and subject lines, to determine whether emails reach the inbox.
4. Your sending infrastructure: This includes your sending domain, click tracking domain, and IP address – all technical components that form the foundation of your email sending capabilities.

A core part of our work was improving deliverability and open rates in order for this marketing channel to be more profitable. We achieved this by focusing on the four areas above, honing each area individually to see overall deliverability increase.

What we did

HubSpot to Klaviyo migration

Prior to our engagement, the brand was using HubSpot to power its email marketing. This project began with migrating all account data from HubSpot to Klaviyo. Klaviyo was identified as a more appropriate tool thanks to its robust and scalable ecommerce-specific features. These include advanced segmentation capabilities, and built-in analytics that provide deeper insights into customer behaviour.

During the Klaviyo migration process, we carefully transferred existing customer data, email templates, and campaign history – ensuring data compliance throughout. This provided an opportunity to clean up the brand’s database and establish proper segmentation from the start, setting a strong foundation for improved deliverability.

Email list segmentation

An important factor for deliverability is segmentation. This is the process of organising your email list into groups of people based on a variety of factors, from engagement and behaviour, to customer profile and preferences.

Before working with us, this brand was sending the same email to its entire list. This approach meant that the least engaged subscribers were receiving emails at the same frequency and with the same content as the most active customers. Not only did this hurt the brand’s deliverability scores as less engaged users were less likely to open emails, but it also meant the brand wasn’t able to tailor messaging and offers to different customer segments effectively.

To address this, we developed a segmentation strategy that began by emailing only the most engaged subscribers – those who had opened or clicked emails within the last 30 days. This allowed us to build positive engagement signals while gradually expanding our sending to wider segments as deliverability improved.

We also created specific segments based on purchase history and browsing behavior, enabling more targeted and relevant messaging.

Strategic email content

Email copy is a powerful tool when engaging with different audiences, in different ways. In tandem with this, sharing high-quality content is vital to build trust with an audience over time.

In this case, we identified areas of content that would resonate with the retailer’s audience while maintaining its position as a performance-focused brand. An example of this was how we shared the story of the brand’s feature in Forbes.

This is a well-regarded magazine by many and the company was included in an article about the rise of personalised supplements. Rather than simply announcing this media coverage, we crafted an email that expanded on the article’s core message about personalisation being the future of supplements. This allowed us to position the brand as a thought leader while reinforcing its unique value proposition.

The email achieved an impressive 41% open rate and generated 13.9% of total Klaviyo attributed revenue over this period – demonstrating how strategic content adaptation can drive both engagement and sales.

The results

Having taken the time to build a strong foundation in Klaviyo, ensuring campaigns, sign-ups and flows were working correctly, we started to see the results of our strategies. Whilst results can often take time to build up with email marketing, we were still able to see the following improvements in just a short timeframe:

• Deliverability score went from <10 to 65 in 90 days.
• Average open rates increased dramatically from less than 10% to 46% – above the 33% target set by the client at the start of our engagement.
• Click rates saw significant improvement, rising from 0.9% to 6.9% – a level that Klaviyo considers ‘Excellent’ by their internal benchmarking standards.

​​Throughout this period of engagement, we continued to test and optimise our approach. One notable insight came from A/B testing the use of emojis in subject lines – something that’s often recommended as email marketing best practice.

Our tests revealed that emails without emojis consistently performed better, showing a 8.9% higher open rate in our first test and a 10.8% improvement in our validation test. This highlighted the importance of testing conventional wisdom against your specific audience, as these customers responded better to a more professional tone that aligned with the brand’s positioning as a science-led health and wellness brand.

Need help improving your email deliverability score?

Overall, these results demonstrate that focusing on deliverability doesn’t mean sacrificing revenue or learning opportunities. By taking a methodical approach to improving email performance – from technical infrastructure to content strategy – we were able to transform email marketing for this exciting brand.

As a full-service Klaviyo marketing agency, we’re well-versed in increasing email deliverability scores for ecommerce brands. This is achieved through a combination of Klaviyo best practice and data-driven strategies, tailored to each brand.

If you need support boosting your email deliverability scores, or other metrics that boost revenue through this high-performance channel, get in touch today.