How we made email authentication actually usable inside editors and AI agents

Annika Grunewaldt — Wed, 17 Dec 2025 09:24:58 +0000

Email authentication is a hidden pain point for developers. You spend days configuring SPF and DMARC only to find emails land in spam or break after adding a new provider. Most tools treat this as a UI problem. That misses the point.

Developers don’t live in dashboards. We live in editors, CI logs, AI workflows, and automation pipelines. We needed a better way to get email auth data where it actually gets used. That’s why we built a Model Context Protocol (MCP) server for email authentication, DNS, SPF, and DMARC.

If you’re not familiar MCP is a standard that lets tools and AI agents query external services as structured programmatic tools. It’s like turning your external systems into real functions you can call from an editor, agent, or script. tools are executable functions and resources with defined schemas that LLMs or clients can invoke directly.

The challenge we solved
Before MCP you needed to:

open your DNS provider console
copy/paste records into a linter
switch tabs back to your editor or terminal
and hope the third party checker matches live DNS

Developers waste context switching and manual steps like this every day. Our MCP server flips that around.

What this MCP server gives you
inside your editor or AI-driven workflow you can now:

query DNS records including DMARC and SPF
validate DMARC policies and SPF syntax
analyze SPF for lookup limits and circular includes
merge SPF records safely before deploying changes

Everything runs read only by design so there’s zero risk of accidental config changes while you’re inspecting state.

Real workflows this unlocks
Imagine in Cursor or VS Code you type:

is this domain safe to send from

and get back a real answer backed by live DNS. Or an AI agent that warns you before merging a PR that your new provider will break SPF. That’s not future talk. That’s today.

Why it matters for devs
The tools we use most are those plugged directly into our workflows. MCP servers make your infrastructure usable like any other developer tool: instantly accessible, scriptable, and composable. This is how real automation and AI assisted development happens in practice.

What’s next
Right now we expose DNS and email auth state via MCP. Next we are bringing DMARC aggregate report data into MCP so you can blend config with real world delivery signals inside the same workflows.

If you’ve ever burned hours debugging subtle SPF or DMARC breaks you know how valuable this can be. If you want to try it, check out the MCP endpoint and let me know what workflows you build with it.

Check it out here: Link we are happy to support and collect feedback!

DEV Community: Annika Grunewaldt

How we made email authentication actually usable inside editors and AI agents