Content
Content & headers
SpamAssassin rules, plain-text vs HTML, trigger words and the headers receivers actually read.
- ·2 min read
Image-to-text ratio: the rule that breaks newsletter design
Why image-heavy emails get filtered, the 60/40 rule that mostly works, and how to design beautiful HTML email without triggering content scanners.
Read - ·2 min read
Accessible HTML email: structure, contrast, and the screen-reader test
Accessibility and deliverability are quietly the same skill. Semantic structure, alt text, and 4.5:1 contrast help filters as much as they help readers.
Read - ·3 min read
Plain text vs HTML email: why both matter (and how to ship both)
Why HTML-only emails get filtered, what a clean multipart/alternative looks like, and the four-line MIME structure to copy.
Read - ·3 min read
Spam trigger words: what actually scores (and what doesn't)
The myth of the trigger-word list, the small set of phrases that genuinely matter, and how SpamAssassin actually weights content.
Read - ·2 min read
List-Unsubscribe and one-click headers
Gmail and Yahoo's 2024 bulk-sender requirements made these headers mandatory. Here's how to implement them correctly.
Read - ·2 min read
Reading SpamAssassin rules — and how to defuse the top 20
SpamAssassin's rule corpus is enormous, but a small handful of rules account for most of the points your campaigns lose.
Read