Email Do’s and Don’ts: Content, Structure, and More

Your email marketing success is rooted in how you manage your lists, authentications, and, most importantly, the way you write, design, and structure your campaigns. 

Understanding email marketing best practices is so important, and to help you avoid common mistakes, I have made a simple checklist of email content do’s and don’ts, from subject lines to structure, and everything in between.

Do: Write Clear and Relevant Subject Lines

Your subject line is the first thing people see, and it's often the trigger of whether your email is opened or ignored. A great subject line sets the tone for your email and helps with writing emails that don’t go to spam.

Best email subject line practices:

• Keep it short and to the point (aim for under 50 characters).
• Be clear and do not use clickbait. A subject line like “Your weekly design tips” works better than “YOU WON’T BELIEVE THIS!!!”
• Add context when and where possible, but don’t overpromise.

Don’t: Use Spammy Language

Email providers are always on the lookout for red flags. Overusing words and phrases like “FREE,” “Act Now,” or writing in all caps can trigger spam filters. Remember, the goal is trust. If your subject line feels like a trick, recipients are more likely to mark your email as spam.

Avoid:

• Misleading subject lines.
• Overly promotional words.
• Excessive punctuation (!!!, $$$).

Do: Personalize and Segment Your Content

People engage more when emails feel relevant. Use personalization strategies. Use first names, location, or company name and pair it with a strong email segmentation strategy to achieve your desired results. 

What this means is:

• Send product recommendations based on past purchases or identified interests. 
• Tailor offers by location.
• Create different versions of a newsletter for active vs. inactive subscribers. 

Don’t: Send Cluttered or Image-Only Emails

A common mistake most people make is cramming too much information into one email or relying only on images. Both can hurt deliverability. The solution? Keep a clean layout, write short paragraphs, and always include meaningful text alongside visuals.

Why it matters:

• Spam filters prefer layouts with balanced text and images. Applying this rule to all your messages will help you evade spam filters and get you into the inboxes of your recipients. 
• Some users block images by default, which means they won’t see your message, especially if it’s an image-only mail.

Do: Follow a Simple Structure

If you are still wondering how to structure a marketing email, here's your cue. Think of it like a mini landing page with all the constituent parts playing individual roles but in synergy. 

1. Header: Branding or logo so readers know who it’s from.
2. Subject line + preview text: Teaser. Tells a bit of what’s inside.
3. Body content: Clear, scannable text with bullet points or short paragraphs.
4. CTA (call-to-action): A button or link that stands out.
5. Footer: Contact info, unsubscribe link, and legal disclaimers.

This is the ideal structure of a marketing email. It ensures your email is both professional and easy to read.

Don’t: Forget Accessibility

One in four people lives with some form of disability. If your email isn’t accessible, you’re excluding a large chunk of your audience. Accessibility is a good practice as it improves engagement and helps keep your campaigns out of spam folders.

Avoid:

• Low-contrast color schemes. This excludes visually impaired audiences. 
• Tiny fonts that don’t render well on mobile.
• Missing alt text on images.

Do: Include a Clear Unsubscribe Option

This might feel counterintuitive, but making it easy to unsubscribe is one of many email marketing best practices. If people can’t find the unsubscribe link, they’ll hit the spam button instead. So, think about it. 

Don’t: Send Without Testing

Before launching a campaign, always test. Testing first, helps you catch small mistakes that could ruin a campaign or worse, damage your reputation.

Test to see:

• How your email looks on desktop and mobile.
• How it renders across different email clients (Outlook, Gmail, Apple Mail).
• Whether links, buttons, and tracking pixels work. 

Final Thoughts

Getting the right results from your campaign requires following set strategies that help to maximize your reach and audience retention. Email content do’s and don’ts is just one of those strategies that can help you achieve measurable success. There are others; you can check them here. 

Above all, always structure your message clearly and put the recipient first. At the end of the day, email marketing is about relationships. And the best way to build those is with clear, valuable, and respectful communication.