
Connect CaptainDNS to ChatGPT via MCP: 3 widgets for DNS audits and deliverability
Add the CaptainDNS MCP server to ChatGPT and use 3 widgets to troubleshoot DMARC/DNS and analyze email headers without leaving the conversation.
Domain-based Message Authentication implementation and policy configuration.
10 articles

Add the CaptainDNS MCP server to ChatGPT and use 3 widgets to troubleshoot DMARC/DNS and analyze email headers without leaving the conversation.

Putting your logo in the inbox: what you actually need to configure in DNS for BIMI, and how to choose between VMC and CMC.

Gmail and Yahoo require a one-click unsubscribe via RFC 8058-compliant List-Unsubscribe headers. Here's the expected format, the server-side POST, and the compliance checklist.

Your logo changed but inboxes still display the old one? It is not only a DNS issue: mailbox providers cache BIMI assets. Discover how the cache layers work and how to plan a smooth BIMI migration.

Starting in November 2025, Google enforces new security requirements for bulk senders: full SPF/DKIM/DMARC authentication, TLS encryption and strict unsubscribe management.

AI-automated phishing emails average a click-through rate of roughly 54%. At scale, automation can make these campaigns up to ×50 more profitable. Both figures come from the Microsoft Digital Defense Report 2025 (MDDR 2025).
DNS Lookup
Choose a DNS record type to search for.
Propagation & diagnostics
Compare resolvers worldwide and inspect returned answers.
Keep history, monitor your zones and automate recurring checks.
Email authentication
Tools to verify and validate your email authentication setup.
Text
Transform, encode and measure your content in seconds.
Text case converter
Convert any block of text to upper or lower case instantly.
Base64 encoder / decoder
Encode or decode any content in Base64 without leaving the browser.
Slug generator
Transform any sentence into an SEO-friendly slug in seconds.
Word & character counter
Measure the length of any text, with instant word and character counts.
Images
Preview and validate your BIMI logos before publishing.
Certificates
Inspect CSRs, BIMI logos and VMC certificates before you deploy.
IP
Look up addresses, owners, reverse records and ranges.