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.
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.
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.
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 |
