Deliverability TestingContent & HTML Checks

Content & HTML Checks

20% of your score. These look at the message itself — the part you fully control on every send.

Spam Word Detection — 4 pts

Checks your subject and body for known spam-trigger words and phrases. Fix rewrite flagged phrases (“FREE!!!”, “act now”, “100% guaranteed”) in plain, specific language.

Subject Line Analysis — 3 pts

Checks subject-line quality — length, excessive capitals, and punctuation. Fix keep it concise and human; avoid ALL CAPS and strings of !!!.

Text-to-Image Ratio — 2 pts

Checks the balance of text vs. images. Why it matters image-only emails are a classic spam signal and break when images are blocked. Fix include meaningful live text alongside images.

HTML Best Practices — 2 pts

Checks the email’s HTML quality. Fix use clean, email-safe HTML; avoid bloated or broken markup, scripts, and unclosed tags.

Checks that the links in your email actually resolve. Fix test every link before sending; remove or repair any that 404 or time out.

Short URL Detection — 2 pts

Checks for URL shorteners (bit.ly and friends). Why it matters shorteners hide the destination and are heavily abused by spammers. Fix link directly, or use a branded tracking domain.

Unsubscribe Header — 2 pts

Checks for a List-Unsubscribe header. Why it matters one-click unsubscribe is now required by Gmail and Yahoo for bulk senders. Fix enable list-unsubscribe headers in your ESP (most do this automatically).

Tracking Detection — 1 pt

Checks for tracking pixels and link wrapping. Fix keep tracking reasonable; excessive or third-party tracking can hurt trust — this is informational more than punitive.

Email Size — 1 pt

Checks the message size against Gmail’s ~102 KB clipping threshold. Why it matters clipped emails hide your footer — including the unsubscribe link. Fix trim bloated HTML and inline CSS to stay under the limit.

Image Alt Text — 1 pt

Checks that images have alt attributes. Fix add descriptive alt text — it improves accessibility and shows useful text when images are blocked.