10 Email Marketing Mistakes You’re Probably Making (and How to Fix Them)

At Thunderbolt, we’ve been delivering powerful results through email marketing in Surrey for years. But time and again, we see many businesses (even well-established one) making the same avoidable email marketing mistakes.

In this article, we’ll walk you through 10 of the most common missteps we see, explain how to fix them, and show you how working with a specialist online marketing agency can elevate your campaigns beyond what you thought possible.

Mistake 1: Neglecting Mobile Users

Approximately 60% of all emails are now opened on mobile devices, according to experts. Yet many businesses continue to send out newsletters and campaigns that simply don’t render well on smaller screens. If your email is difficult to read or interact with on a smartphone, your audience is likely to delete it instantly.

To fix this, always design with mobile-first in mind. Use responsive templates that adapt seamlessly to different devices and test your emails on multiple screen sizes before hitting send. At Thunderbolt, we craft mobile-optimised campaigns for clients across Surrey and beyond, ensuring their messages reach customers wherever they are.

Mistake 2: Ignoring Segmentation

Too often, businesses blast the same email to their entire list, regardless of who the recipients are. This blanket approach ignores the fact that different segments of your audience have different needs, preferences and behaviours.

Instead, segment your audience based on factors like demographics, purchase history, or engagement level. A tailored message is far more likely to convert. We’ve helped many clients refine their lists and improve open rates significantly through smart segmentation strategies.

Mistake 3: Using Weak Subject Lines

Your subject line is the very first impression you make, determining whether your email gets opened or ignored. Bland or generic subject lines are a surefire way to torpedo your campaign’s success.

Write compelling, concise subject lines that spark curiosity without resorting to spammy tricks. Personalisation can also boost open rates by 26%, according to Campaign Monitor. As experts in email marketing in Surrey, we test subject lines rigorously to ensure they perform at their peak.

Mistake 4: Not Testing Your Emails

Far too many businesses skip testing altogether, assuming that what looks good in their email editor will look good in their customer’s inbox. Unfortunately, that’s rarely the case.

Every email should be tested across multiple email clients (like Gmail, Outlook and Apple Mail) and devices before you send it. This helps you catch broken layouts, missing images, or formatting issues that could undermine your message. At Thunderbolt, testing is a core part of our quality control process, giving you peace of mind that your emails will shine.

Mistake 5: Overloading on Images

While attractive visuals can enhance your message, relying too heavily on images can harm deliverability and accessibility. Some recipients’ email clients block images by default, meaning they may see a blank email if your content is all graphics.

Strike a balance by pairing well-designed visuals with clear, engaging text. Use alt text for images so your message still gets across even if the visuals don’t load. We help our clients create emails that look beautiful without compromising usability or effectiveness.

Mistake 6: Ignoring Analytics

If you’re not measuring the performance of your email campaigns, you’re essentially flying blind. Yet many businesses fail to track metrics like open rates, click-through rates, and conversions. Or worse, they collect the data but don’t act on it.

Make analytics a priority. Use insights from past campaigns to continually refine your approach. For example, if you notice a high bounce rate, it might be time to clean your list. At Thunderbolt, we analyse every campaign to ensure we’re learning and improving for our clients.

Mistake 7: Sending Too Frequently (or Not Enough)

Finding the right sending frequency is an art; send too often, and you risk annoying your audience, but send too infrequently, and you risk being forgotten altogether.

The fix is to find a rhythm that suits your audience’s expectations and behaviour. This might mean weekly updates for some businesses, or monthly for others. We work with our clients to determine the optimal schedule and keep their audiences engaged without feeling overwhelmed.

Mistake 8: Overlooking GDPR and Privacy Laws

Since the introduction of GDPR, businesses in Surrey and across the UK have had to be far more careful about how they collect, store and use personal data in email marketing campaigns. But some companies still cut corners, exposing themselves to hefty fines and reputational damage.

Ensure that all your subscribers have explicitly opted in, and make it easy for them to unsubscribe. We guide our clients through GDPR compliance to help protect them and their customers alike.

Mistake 9: Failing to Provide Value

If your emails are purely promotional or self-serving, you’ll quickly lose subscribers. Today’s audiences expect content that’s informative, entertaining, or otherwise valuable.

Fix this by offering something useful in every email, whether it’s exclusive insights, how-to guides, discounts, or early access to new products. At Thunderbolt, we help businesses in Surrey craft content that keeps their subscribers looking forward to the next message.

Mistake 10: Trying to Do It All Yourself

Perhaps the biggest mistake we see businesses make is trying to handle email marketing entirely in-house, without the necessary expertise, tools, or time. The result is often underwhelming campaigns that fail to deliver a meaningful return on investment.

That’s where we come in. As a leading email marketing agency in Surrey, we partner with businesses to create and execute email strategies that truly work. From strategy and design to delivery and analytics, we take care of everything, leaving you free to focus on running your business.

Why Choose Thunderbolt for Email Marketing in Surrey?

Email marketing remains one of the most cost-effective forms of digital marketing in the UK, boasting an average ROI of £42 for every £1 spent (according to the Direct Marketing Association). But to achieve these kinds of results, you need to avoid these common mistakes and work with experts who understand the nuances of the medium.

At Thunderbolt, we offer a full suite of online marketing services, with email marketing at the heart of what we do. Our team combines creative flair, technical know-how, and data-driven strategy to deliver campaigns that cut through the noise and get results.

Whether you’re a small business looking to grow your customer base or an established brand wanting to revitalise your campaigns, we can help you get more out of your email marketing.

Avoid Email Marketing Mistakes with Our Expert Advice

If you’re ready to stop making these email marketing mistakes and start seeing real results, we’d love to hear from you. Based in Surrey, we’re proud to help businesses across the county and beyond achieve excellent email marketing results.

Let us help you transform your email marketing into a powerful driver of growth. Contact us today to discuss your goals and see how we can work together to achieve them.