Blog
Email Deliverability Guides & Best Practices
Guides, best practices, and intelligence from the InboxEagle team to help you land in the inbox every time.
E-commerce6 min
The Ecommerce Email Deliverability Gap: What Top Brands Do Differently
InboxEagle analyzed 3,474 ecommerce sender domains and found a 72-point inbox placement gap between the best and worst performers. Here's the ecommerce email performance benchmark — and what separates top-quartile brands from everyone else.
E-commerce6 min
Do Aggressive Sale Subject Lines Hurt Deliverability? What Our Data Shows
Sale language doesn't automatically hurt deliverability — but some patterns do. InboxEagle analyzed 721,351 emails and found results that flip conventional wisdom on its head.
Authentication6 min
BIMI in 2026: Google's CMC Makes Brand Logos Affordable for Everyone
Google launched a Common Mark Certificate option for BIMI in 2025 — no trademark required. Here's how BIMI works, what's changed, and whether it's worth implementing for your email program.
Gmail6 min
Microsoft Outlook's Bulk Sender Requirements: What Email Marketers Need to Know
Microsoft began enforcing bulk sender requirements for Outlook, Hotmail, and Live.com on May 5, 2025. Non-compliant mail gets a 550 5.7.515 rejection. Here's exactly what's required and how to comply.
E-commerce8 min
Ecommerce Email Benchmarks 2026: Inbox, Promotions & Spam
InboxEagle analyzed 721,351 ecommerce emails in Q1 2026. Here's where they landed — Primary, Promotions, and Spam — and what the data means for your sending program.
Gmail13 min
Where Your Email Lands: Inbox, Promotions, or Spam?
Most senders track delivered vs. spam. But Gmail has a third folder — the Promotions tab — that quietly buries marketing emails just as effectively. Here's what determines where your email lands, and how to see all three outcomes before you send.
Authentication3 min
Email Deliverability Checklist: 30 Pre-Send Checks
A complete pre-send checklist covering authentication, sender reputation, list hygiene, content, and monitoring — updated for 2026 enforcement requirements.
Gmail6 min
How Email Spam Filters Work: What ISPs Check Before Delivering Your Email
A technical but accessible explanation of how Gmail, Outlook, and Yahoo decide whether your email reaches the inbox or the spam folder.
Analytics5 min
How AI Monitors Email Deliverability: What's Actually Different
AI-powered deliverability monitoring alerts you in under 1 minute, identifies root causes, and generates action plans — here's exactly how it works differently from traditional dashboards.
Analytics4 min
What Is a Good Inbox Placement Rate? 2026 Benchmarks
Industry benchmarks for inbox placement rates across eCommerce, SaaS, and B2B — and what to do if yours falls short.
Analytics6 min
Inbox Placement vs. Delivery Rate: Know the Difference
Your ESP says 99% delivered. But how much of that mail actually reached the inbox? The difference between delivery rate and inbox placement rate — and why it matters enormously for revenue.
Analytics8 min
Why Your Email Open Rate Is Lying to You (And What to Track Instead)
Apple Mail Privacy Protection and security scanner pre-fetching have made open rate an unreliable metric. Here's what's happening, why high open rates can be a warning sign, and what to measure instead.