Should I use HTML or plain text emails?
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A sales rep sends 200 personalized plain text emails and books 30 meetings. A newsletter team spends a week polishing an HTML template and gets a 2% click rate. Neither approach is wrong: they're solving different problems for different audiences. The real question isn't which format is better; it's which format matches what you're trying to accomplish with this specific email.
Most modern email senders actually send both at once. The technical term is multipart MIME: your email contains an HTML version and a plain text version, and the recipient's email client automatically displays whichever one it handles best. If your ESP supports multipart MIME (and most do), you should be using it for newsletters and promotional sends. The plain text part isn't just a fallback; it's also what gets read by some spam filters and deliverability tools, so a well-written plain text version can help your sender reputation hold steady when the HTML version is complex.
HTML email makes sense when you need visual brand consistency, images, multi-column layouts, or trackable CTA buttons. It's the right choice for newsletters, promotional campaigns, product announcements, and most transactional emails where formatting matters. The trade-off is that HTML is more likely to trigger overly aggressive spam filters if your code is messy, and tracking pixels in HTML emails are now less reliable since Apple Mail Privacy Protection (introduced in iOS 15) pre-fetches images, inflating open counts. If you're using opens to measure engagement or segment your list, click-based metrics are more reliable signals regardless of which format you send.
Plain text email is the right choice for cold outreach, B2B relationship-building emails, and situations where you want the message to feel like it came from a person rather than a marketing system. Plain text emails often have lower unsubscribe rates in these contexts because they don't feel like ads. They also sidestep some authentication and tracking complexity, though they're not inherently more deliverable than well-coded HTML on a reputable sending domain.
The practical starting point: use multipart MIME for any marketing or newsletter send, use pure plain text for personal outreach and relationship emails, and test both with Review My Emails' template checker to see how they render across clients before committing to a format for your next campaign.
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