How Does Email Rendering Affect Email Marketing Campaigns?

Your subscribers open their email on a range of devices. Some might start reading on a mobile phone and finish it later on a laptop or tablet. Which means, as an email marketer, it’s important to get email rendering right.

In this blog, we will explore seven ways email rendering can affect your campaigns so you can be proactive in your efforts and better serve your subscribers.

What exactly is email rendering?

Email rendering is basically how your email looks when someone opens it in their inbox. It can show the layout, fonts, images, buttons, and all the other design elements.

The tricky part is that different email clients, like Gmail, Outlook, or Apple Mail, display HTML and CSS in their own way. Some styles might not be supported or could be changed, which can make your email look broken or messy.

5 ways email rendering affects email marketing campaigns

Here are five ways email rendering affects your email marketing campaigns:

1. Brand credibility

The moment a subscriber opens an email, they form a judgment about the brand. Emails that render poorly like broken layouts, missing images, or misaligned buttons, immediately reduce trust.

On the other hand, emails that render properly reinforce brand credibility. It conveys that the company pays attention to detail, cares about the user experience, and can be trusted.

2. Readability

A major challenge in email marketing is the wide variety of email clients and devices that recipients use. Gmail, Outlook, Apple Mail, and countless mobile apps all interpret HTML and CSS differently. A design that looks perfect in one client may break in another.

Rendering issues can affect readability in several ways. Like:

• Text may appear too small

• Columns could stack improperly

• Buttons may become difficult to tap on mobile

• Essential content could disappear entirely if certain HTML elements are unsupported.

If users struggle to read or interact with your email, engagement inevitably drops. Subscribers are unlikely to scroll through an email that is visually chaotic or impossible to navigate.

3. Conversion

The ultimate goal of many email campaigns is to drive clicks and conversions. However, if your conversion CTA isn’t functioning correctly, like it's invisible or hard to tap, every effort you’ve put into your copy, design, and targeting is wasted.

To prevent this, it’s essential to test your emails across multiple devices and clients, ensuring that CTAs are clearly visible, easy to tap, and positioned strategically.

Tools like Mailmodo’s offera preview and test feature let you see exactly how your email will render across different devices and email clients before you hit send.

4. Accessibility and inclusivity

Email rendering also impacts accessibility. Assistive technologies, such as screen readers, rely on properly structured HTML to interpret content for users with visual impairments. Poor rendering can break this flow, making emails difficult or impossible to understand.

Other accessibility concerns include text contrast, legibility, and logical hierarchy. If headings, paragraphs, and interactive elements are not correctly coded, screen readers may misinterpret them, leaving users confused.

5. Deliverability

While rendering does not directly determine whether an email lands in the inbox, it influences metrics that affect deliverability. Low engagement rates, caused by broken or poorly rendered emails, can harm the sender's reputation. Spam filters also look for certain red flags, such as image-heavy emails without proper alt text, broken HTML, or unusual coding.

Well-rendered emails support healthier engagement signals, such as higher open rates and click-throughs. Consistent positive interactions indicate to email providers that your content is trustworthy, reducing the likelihood of being flagged as spam.

Bottom line

Proper email rendering is a key factor in how your subscribers experience your brand. From first impressions and readability to clicks, conversions, and accessibility, every aspect of your email performance depends on how well your content displays across devices and email clients.

By testing your emails, optimizing layouts for mobile, and ensuring that CTAs, images, and text render correctly, you can avoid broken experiences that frustrate readers and hurt engagement.