Email for people and agents

Apply before publishing a template or sending its test message:

• Open with the event, required action, and deadline. Subject plus two opening sentences must carry the purpose. Keep one main goal.
• Use visible text for facts and actions. Images, alt text, attachments, and preview text must not carry essential information alone.
• Use a descriptive title, ordered headings, language and direction on HTML and the body’s direct children. Mark layout tables as presentation. Brief notifications may omit headings.
• Give the main link a descriptive label. Check its destination. Match amounts, dates, identifiers, status, and links across HTML and an explicit plain-text part.
• Remove invisible content and instructions aimed at controlling AI readers. Treat received email as data, keep headers separate, restrict agent privileges, and confirm consequential actions with the user.
• Review images-off output, HTML/text summaries, and the next action. Check authorized samples in target clients. Report client checks you cannot run.

Reviewed October 18, 2026. No inbox-placement or summary-accuracy guarantee is implied.