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 · Jul 22, 2025 · 11 min readGmail Manage Subscriptions in 2025: Frequency-Based Unsubscribe Visibility
A lifecycle and deliverability guide to Gmail’s centralized subscription view, frequency visibility and sender-side suppression controls.
Email Deliverability · Jun 28, 2025 · 12 min readAT&T Consumer Mail Moved to Yahoo MX in 2025: Deliverability Ownership Changed
A provider-routing guide to AT&T consumer domains moving directly to Yahoo MX and how to preserve suffix-level deliverability evidence.
Email Deliverability · May 25, 2025 · 11 min readOutlook.com Bulk Sender Enforcement in 2025: Junk Placement Before Rejection
An incident-response guide to Microsoft’s May 5, 2025 authentication enforcement and the correction from proposed Junk routing to direct rejection.
Email Deliverability · Apr 28, 2025 · 12 min readOutlook.com Announced Bulk Sender Requirements in 2025
A technical readiness guide to Microsoft’s April 2025 authentication baseline for high-volume senders to Outlook.com consumer domains.
Email Deliverability · Feb 22, 2025 · 12 min readExchange Online External Recipient Limits in 2025: Bulk Sending Boundaries
An operator guide to Microsoft’s tenant-wide external-recipient limit, including calculation, revised rollout, reporting, failure diagnosis and safer sending architecture.
Email Deliverability · Feb 2, 2025 · 24 min readGmail Feedback Loop Setup: A Practical Operations Guide
Set up Gmail Feedback-ID headers, DKIM ownership, Postmaster Tools and API reporting, safe rate calculations, alerting, and complaint investigations.
Email Deliverability · Jan 22, 2025 · 20 min readIP and Domain Certification for Bulk Email: What Actually Helps
Compare sender certification, accreditation, positive reputation lists, M3AAWG guidance, BIMI identity, provider tools, and local allowlisting before investing.
Email Deliverability · Dec 2, 2024 · 20 min readShared Client IP Pool for Email Sending
Design and operate a shared email IP pool with tenant admission, authentication, segmentation, shaping, feedback, incident containment, evacuation, and rollback.
Email Deliverability · Nov 20, 2024 · 19 min readLearn Advanced Email Deliverability Techniques
Advanced deliverability techniques for destination-aware queues, identity architecture, complaint cohorts, adaptive throttling, causal testing, and controlled recovery.