Lowercase vs Uppercase in Emails: Best Practices | Case Modify

By Case Modify Editorial · Published April 21, 2025 · Updated July 21, 2026

Email capitalization guidelines for subject lines, preview text, body copy, and buttons—without sounding robotic or spammy.

Subject lines

Sentence case or title case both work; all-caps subject lines often trigger spam associations and feel aggressive in crowded inboxes. Lead with the benefit or question, then add a concise qualifier: “Your export is ready” or “Q3 roadmap review.”

Body copy

Use normal sentence case for paragraphs. Reserve uppercase for acronyms and defined terms on first use. Avoid typing entire sentences in caps for emphasis—use bold sparingly in rich HTML instead.

Buttons and CTAs

Product-led companies increasingly use sentence case on buttons (“Download report”) because it matches in-app UI. Marketing emails may use title case on primary CTAs (“Get Started Free”) for contrast—stay consistent within a campaign.

Signatures and legal footers

Legal disclaimers are often uppercase in legacy templates. If you modernize templates, convert disclaimers to sentence case with smaller font size for readability, unless counsel requires exact legacy formatting.