Gmail & Google Postmaster Guides
Understand Gmail's spam filters, monitor your domain reputation, and take action when your inbox placement drops.
Gmail9 min
Gmail Emails Going to Spam? What 514K Messages Show
Your ESP dashboard says delivered. Then you check Gmail and find it in Spam. We tracked 514,492 Gmail-bound ecommerce messages between 11 June and 11 September 2026: 25% landed in spam, and unauthenticated mail was more than twice as likely to get filtered. Here's what actually moves the needle — authentication, ESP choice, and sending volume — and what a blended, all-provider dashboard hides about your Gmail-specific problem.
Gmail8 min
List-Unsubscribe Header: Does It Actually Reduce Spam Rates?
Does the List-Unsubscribe header actually lower spam rates? InboxEagle's study of 19,797 brands reveals a 4.86x extreme spam risk for senders without it.
Gmail7 min
The Correlation Between High Sending Frequency & Spam Complaints
Does sending more emails mean more spam complaints? InboxEagle analyzed 31,586 sending programs — the data tells a more nuanced story than you think.
Gmail8 min
Gmail Spam Rate Thresholds: What 0.10% and 0.30% Actually Mean for You
Gmail enforces two spam rate thresholds that most senders misread. Here's exactly what 0.10% and 0.30% mean, how they're measured, and what to do before you breach either one.
Gmail8 min
Gmail Promotions vs Spam: Where 671K Ecommerce Emails Landed
We measured Gmail placement for 671,329 emails across ~19,400 ecommerce senders in Q1 2026. Brand-level deliverability turns out to be close to binary — and the middle ground barely exists.
Gmail7 min
Gmail Deliverability Benchmarks for Ecommerce Brands: Q1 2026 Data
InboxEagle monitored 721,351 emails to Gmail in Q1 2026. Here are the real gmail deliverability benchmarks — spam rates, tab placement, and what separates healthy programs from at-risk ones.
Gmail6 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.
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.
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.
Gmail7 min
Google Postmaster Tools v2: The Complete Setup and Interpretation Guide
How to set up Google Postmaster Tools v2, read the Compliance status dashboard and its Deliverability analysis verdict, and plan for the reputation scores Google has said it will retire.