Should I use HTML or plain text emails?

The answer depends on purpose, brand, and audience. Most marketing emails benefit from HTML-visual branding, layouts, images, and clickable buttons all require it. But plain text has legitimate uses and advantages in specific contexts.

HTML advantages: Branding, visual hierarchy, images, buttons, tracking pixels, responsive design. Plain text advantages: Universal rendering, personal feel (like real email), no image blocking issues, sometimes higher reply rates for 1:1 style communications, guaranteed dark mode compatibility.

Send both when possible. Multipart emails include HTML and plain-text versions; the recipient's client chooses which to display. Always write a proper plain-text version-don't just strip tags. Some recipients prefer plain text; others have clients that default to it. Covering both bases is professional practice.