GuideComplianceRequirementsSubject & Body

    Subject Line & Body Content

    Rules and best practices for accurate subject lines and compliant body content under CAN‑SPAM, CASL, and GDPR.

    The subject line and body of every email must accurately reflect the intent of the message. Deceptive subjects and misleading body content are explicitly prohibited by CAN‑SPAM and CASL.

    Required — CAN‑SPAM, CASLBest Practice — GDPR

    What it is

    The subject line is what the recipient sees in their inbox before opening an email — it must be a truthful description of the message's intent. The body is the visible content of the email itself — it must match the promise made by the subject and must not contain hidden scripts, invisible text, or misleading links.

    Why it's needed

    CAN‑SPAM and CASL explicitly prohibit false or misleading subject lines. Under GDPR, misleading content may constitute unfair data processing. Deceptive subjects and body content sharply increase spam complaint rates and hurt inbox placement — and can result in account suspension on Simply Send.

    Subject line guidelines

    • Write subject lines that truthfully reflect the email content — be specific and concise.
    • Avoid "Free!", "Urgent!", "Winner!", or "Act Now!" unless strictly accurate.
    • Keep the subject under 78 characters for optimal rendering across all major email clients.
    • Do not use ALL CAPS — it triggers spam filters.
    Avoid: "OPEN IMMEDIATELY", "You've won a prize!", or any subject that misrepresents the email content. These violate CAN‑SPAM and are flagged by virtually all spam filters.

    Body content guidelines

    • Body content must match the intent described in the subject line — do not bait-and-switch.
    • Avoid hidden scripts, invisible text (e.g., white text on white background), or deceptive anchor links that obscure the actual destination URL.
    • Branding (logo, sender name, domain) in the body must match the sending domain verified in Simply Send.
    • Do not embed tracking pixels or scripts from unverified third parties — these are blocked by Simply Send's outbound email policy.
    Tip: Simply Send scans outbound email content for common spam indicators before send. Emails that fail content checks will be held for review.

    Subject line examples

    ✗ Non‑Compliant✓ Compliant
    YOU'VE BEEN SELECTED!!!Your application has been reviewed
    FREE GIFT inside — open now!Acme Corp: 20% off this weekend only
    RE: Your request (unprompted)Your June newsletter from Simply Send