Deliverability and rendering, explained plainly
Short, specific write-ups on why real templates break and why real emails misroute, grounded in the same rule engine and rendering research behind the analyzer itself.
Why Your Emails Land in Promotions, Not Primary
Gmail's tab placement isn't spam filtering: it's a separate categorizer, and it reacts to different signals than the ones that get you blocked outright.
Rendering"Outlook" Isn't One Email Client: It's Three
Classic Outlook for Windows, the new WebView2 Outlook, and Outlook for Mac render HTML email three genuinely different ways. Testing only one and calling it "Outlook-safe" is how bugs ship.
Case StudyThe Domain Was Fine. The Template Wasn't: a Real Before/After
A real sender with clean domain and IP reputation ran the same four-email sequence twice: once before fixing template-level issues, once after. Every send moved out of Spam. Nothing else changed.
AnalyticsApple Killed Your Open Rate in 2021 (Nobody Told You)
Since iOS 15, Apple Mail pre-fetches every tracking pixel the instant a message is delivered, whether a human ever opens it or not. Your open rate has been measuring something else for years.
RenderingWhy Your Email Looks Broken in Dark Mode
A template that renders perfectly in a light-mode test send can turn into invisible text on a black box the moment a phone is in dark mode, and the reason isn't a CSS mistake. It's that clients handle an unspecified template completely differently.
RenderingThe 102KB Cliff: Why Gmail Clips Your Email
Gmail doesn't warn a sender and doesn't bounce the message. Past roughly 102KB it silently stops rendering partway through, right around where most templates keep their unsubscribe link and tracking pixel.