Blog
Email developer resources
Guides on CSS inlining, HTML minification, deliverability, and everything in between.
01
How CSS Inlining Works — And Why Your ESP Requires It
Gmail strips style blocks. Outlook ignores them. Here's why CSS inlining exists, how it works, and what happens when you skip it.
May 14, 2026
02
Spam Words That Kill Email Deliverability in 2026
Spam filters have evolved beyond simple keyword matching, but certain words and phrases still reliably tank deliverability. Here's what to avoid and why.
May 6, 2026
03
Why Generic HTML Minifiers Break Email Templates
Most HTML minifiers are built for the web, not the inbox. Here's what they strip out, and why it matters for Outlook, Gmail, and your email deliverability.
May 2, 2026
04
The Email Developer's Pre-Send Checklist
A practical checklist covering HTML, CSS, deliverability, and content: everything to verify before your email hits the inbox.
April 25, 2026