Email marketing has a reach problem that most senders do not think about. Campaigns are carefully designed, tested across devices, and A/B tested for subject lines — and then sent to subscribers who use screen readers, dark mode, or images-off settings and receive something that is confusing, broken, or completely unreadable. Accessible email is not a niche concern. It is the difference between a message that reaches your audience and one that does not.
Accessibility starts with the subject line
Before anyone opens your email, they read the subject line. Often, they hear it — screen reader users navigate inboxes by listening to subject lines read aloud:
- Keep subject lines clear and descriptive — they should communicate the email’s value without needing to open it.
- Use preheader text to complement the subject line and add context.
- Avoid special characters, emoji, or symbols as the primary carriers of meaning — screen readers read these aloud in ways that are often confusing.
- Be honest about what is inside. Vague or misleading subject lines frustrate everyone, but they are especially disorienting for users navigating by audio.
Structure your HTML properly
The visual presentation of an email and its underlying markup are two different things. Screen readers work from the markup, so a beautiful-looking email can still be completely inaccessible:
- Use real heading tags (
<h1>,<h2>,<h3>) to organise content — not bold, large-font text that only looks like a heading. - Build layout with semantic table markup where needed, ensuring the HTML reading order matches what users see.
- Use
<p>tags for body text, not repeated<br>tags for spacing. - Clean up layout hacks: empty table cells, invisible spacer images, and redundant divs all create unnecessary noise for screen readers.
Write alt text for every meaningful image
Many email clients block images by default. Screen reader users never see them at all. Alt text is not an optional extra — it is the content:
- Write descriptive alt text for every meaningful image — logos, product photos, hero banners, infographics.
- Decorative images and spacers should use an empty alt attribute (
alt="") so they are skipped silently. - Never put critical information — an offer, a price, a call to action — only inside an image. If the image does not load, that information disappears entirely.
- For image-based buttons, the alt text should describe the action: “Shop the sale” rather than “button.jpg”.
Color contrast matters in email too
Email designs often prioritise brand aesthetics, and this is where contrast problems tend to creep in:
- Body text needs a minimum contrast ratio of 4.5:1 against its background. This rules out the light grey on white that appears in far too many newsletters.
- Test in dark mode — many email clients now support it, and it can dramatically alter how your colors appear.
- Linked text must be distinguishable from surrounding content through more than just color — underlining is the simplest and most reliable approach.
Mobile accessibility is non-negotiable
The majority of email is now opened on a phone, and mobile accessibility and responsive design overlap significantly:
- Use single-column layouts that reflow cleanly on small screens without horizontal scrolling.
- Buttons and links need tap targets of at least 44×44 pixels and enough spacing to prevent accidental taps.
- Set a minimum body font size of 16px on mobile so text is readable without pinching to zoom.
- Do not disable pinch-to-zoom — some users rely on it to read comfortably.
Test across clients, not just your own inbox
Email rendering is inconsistent in ways that web browsers are not. What looks perfect in Apple Mail can break in Outlook:
- Use tools like Litmus or Email on Acid to preview across dozens of clients and devices simultaneously.
- Test with a screen reader (VoiceOver or NVDA) to verify reading order and that all content is announced correctly.
- Check your HTML with an email accessibility checker to catch common issues before sending.
- Include images-off testing — view your email with images blocked and ask whether it still makes sense.
What it comes down to
An accessible email does not require a different creative approach — it requires better execution of the same creative vision. Clear subject lines, real HTML structure, meaningful alt text, sufficient contrast, and mobile-friendly layouts are all just good email practice. The subscribers who benefit most are those who currently receive something that does not work for them at all. Everyone else gets a better email too.