NitWings Insights
Technical Insights
Practical field notes for teams diagnosing email deliverability, DNS authentication, sender reputation, Linux, MTA, cloud, monitoring, and DevOps failures.
Articles on email deliverability, DNS, Linux, MTA operations, DevOps, monitoring, and incident recovery.
Short, practical guidance for teams that need to diagnose, repair, and run production email systems.
Browse by issue, provider, workflow, or stack area when you need a fast starting point for investigation.
Email Deliverability · Oct 28, 2016 · 13 min readOutlook Focused and Other Inbox in 2016: A New Visibility Layer
A technical history and operating guide to Outlook Focused and Other classification, user training, visibility measurement and deliverability diagnosis.
Email Deliverability · Sep 24, 2016 · 11 min readGmail Responsive CSS Support in 2016: What Changed for Email Rendering
A dated technical analysis of Gmail’s 2016 support for style blocks, selectors and media queries, with current coding and QA guidance.
Email Deliverability · Mar 25, 2016 · 12 min readYahoo Expanded DMARC Reject Policies in 2016: International Domain Impact
A dated analysis of Yahoo’s March 28, 2016 DMARC expansion across 62 international domains and the operational response required from senders.
Email Deliverability · Feb 28, 2016 · 13 min readGmail TLS and Authentication Warning Icons in 2016: Trust Became Visible
A dated technical analysis of Gmail’s 2016 TLS and authentication warnings, their limitations, sender impact and current remediation workflow.
Email Deliverability · Jul 28, 2015 · 12 min readGmail Neural-Network Spam Filtering in 2015: Personalized Classification Arrives
A dated technical analysis of Gmail’s July 2015 neural-network filtering expansion, personalized preferences, impersonation signals and sender response.
Email Deliverability · Jul 21, 2015 · 13 min readGmail Postmaster Tools Launched in 2015: New Evidence for High-Volume Senders
A dated operational analysis of Gmail Postmaster Tools, from its July 2015 launch to the current v2 dashboards, API and diagnostic workflow.
Email Deliverability · Mar 28, 2015 · 13 min readDMARC Became RFC 7489 in 2015: What the Standard Changed for Senders
A dated technical analysis of DMARC’s March 2015 RFC milestone, alignment, policy, reporting and the Standards Track specifications that replaced it in 2026.
Email Deliverability · Apr 27, 2014 · 14 min readYahoo DMARC Reject Policy in 2014: The Impact on Third-Party Sending
A dated analysis of Yahoo’s early-April 2014 strict DMARC policy, including anti-spoofing value, indirect-mail failures, mailing-list mitigations and current practice.
Email Deliverability · Apr 22, 2014 · 14 min readAOL DMARC Reject Policy in 2014: Mailing List and ESP Consequences
A dated technical analysis of AOL’s April 22, 2014 DMARC reject policy, including the security benefit, indirect-mail failures and current sender actions.