Early access

Mailgun MCP server

Name: Arc0 for Mailgun
Author: Arc0

Inspect sending domains, delivery events and suppression records before sending an authorized email. Access is gated: request enablement for your organization before connecting.

Request early access See 9 actions ↓

EmailAPI keyMCP + RESTmailgun.com

AUDIT LOG · MAILGUNPOLICY: acme-support

09:41:07 · claude · u_8f2read

mailgun.list_events

List events✓ allowed · 212ms

09:41:08 · claude · u_8f2read

mailgun.get_stats

Get stats✓ allowed · 164ms

09:41:09 · claude · u_8f2write

mailgun.send_email

Send email✓ approved · approved by user

ILLUSTRATIVE POLICY TRACE · NOT A LIVE RECEIPT

01 · USE CASES

Agent workflows for Mailgun.

List domains

Use when discovering sending domains and their verification state. Returns one bounded page; total_count is the full matching count. Does not expose SMTP credentials.

Get domain

Use when checking the connected sending domain and its verification state. The domain is fixed by the connection; SMTP credentials and DNS payloads are excluded.

Send email

Use when sending authorized text email from the connected domain to one recipient. test_mode defaults true (no delivery, still billed); false notifies them. Suppressed recipients are silently dropped; queued is not delivered. No unsolicited mail or blind retries; reconcile first (no idempotency).

02 · ACTIONS

9 Mailgun actions, graded by risk.

These actions come from the Arc0 registry. Your identity, provider permissions and Arc0 policies determine which actions can run.

read

Look things up, subject to your permissions.

mailgun.list_domains
List domains
Use when discovering sending domains and their verification state. Returns one bounded page; total_count is the full matching count. Does not expose SMTP credentials.
mailgun.get_domain
Get domain
Use when checking the connected sending domain and its verification state. The domain is fixed by the connection; SMTP credentials and DNS payloads are excluded.
mailgun.list_events
List events
Use when reconciling one recipient by message ID within seven days; returns a bounded first page. Events API is deprecated for Logs. Retention depends on plan: an empty old window does not prove no send occurred. Event IDs differ from message IDs.
mailgun.list_bounces
List bounces
Use when inspecting permanent delivery failures on the connected domain. Returns only the first bounded page, optionally filtered by address prefix; not an export. Never use this to reverse a recipient opt-out.
mailgun.list_unsubscribes
List unsubscribes
Use when inspecting recipient opt-outs on the connected domain. Returns only the first bounded page, optionally filtered by address prefix; not an export. Never use this to reverse a recipient opt-out.
mailgun.list_complaints
List complaints
Use when inspecting spam complaints on the connected domain. Returns only the first bounded page, optionally filtered by address prefix; not an export. Never use this to reverse a recipient opt-out.
mailgun.get_unsubscribe
Get unsubscribe
Use when checking whether one exact recipient has an unsubscribe record on the connected domain. Returns structural status only; a missing record is not consent to send. Never use to remove an opt-out.
mailgun.get_stats
Get stats
Use when checking daily delivery or engagement totals for the connected domain over at most 31 days. Legacy Stats API is deprecated in favor of Metrics. Omitted counters stay absent rather than becoming invented zeros.

write

Create and change things. Allow, or ask the user first.

mailgun.send_email
Send email
Use when sending authorized text email from the connected domain to one recipient. test_mode defaults true (no delivery, still billed); false notifies them. Suppressed recipients are silently dropped; queued is not delivered. No unsolicited mail or blind retries; reconcile first (no idempotency).

destructive

Delete, cancel or archive. Ask first, or deny outright.

No destructive actions.

03 · POLICIES AND AUDIT

Control access to Mailgun.

After early access is enabled, connect the intended Mailgun account, authorize your AI client and set policies for its tools.

Provider permissions and Arc0 policy both apply. Allow reads, require approval for selected writes, or deny destructive actions. The audit log records execution decisions.

Configure policies and approvals

Example policy choices

Read actions: allow where authorized
mailgun.send_email: require approval

Arc0 MCP endpoint: https://api.arc0.ai/mcp

04 · AUTH AND DATA

How Mailgun connects.

Connect Mailgun using API key. OAuth grants the provider scopes shown during consent; API keys and other credentials retain the permissions configured at the provider. Arc0 stores credentials in its encrypted vault and does not pass them to the model. Disconnect to remove access through Arc0; revoke a key at the provider to invalidate it there. Token refresh and provider-side revocation depend on the authentication lane and provider.

The connection serves authorized calls through Arc0 MCP and REST. How Arc0 handles credentials →

AUTH: API key
CREDENTIALS: Per-tenant encrypted vault
MODEL SEES: Results only, never credentials
AUDIT LOG: Every call, on every plan

05 · AI CLIENTS

Use Mailgun with your AI client.

Request access to Mailgun first. An Arc0 administrator must enable it for your organization before these actions appear. Then authorize your AI client separately. It only receives tools and accounts allowed for that identity.

Mailgun with Claude

Claude Desktop + Claude Code

In Claude Desktop, add Arc0 through the remote MCP settings and use OAuth. Follow the generic remote-client steps if your account’s interface differs.
For Claude Code, run the command below. Open /mcp, select Arc0, and authenticate in your browser. Select your workspace and review access.
Check the connection with claude mcp get arc0.

claude mcp add --transport http --scope user arc0 https://api.arc0.ai/mcp

Full MCP setup and troubleshooting

All apps for Claude

Mailgun with ChatGPT

ChatGPT on the web

Open Plugins in ChatGPT, select the plus button, then Add custom MCP server.
Name it Arc0, enter the server URL below, and choose OAuth. Use dynamic client registration if asked; no Arc0 API key is needed.
Review the notice and select Create as a plugin. Complete Arc0 sign-in, workspace selection and consent, then install and select the plugin in your conversation. Labels and access vary by account; managed workspaces may require administrator approval.

https://api.arc0.ai/mcp

Full MCP setup and troubleshooting

All apps for ChatGPT

Mailgun with OpenAI Codex

Codex app + CLI

Run the registration command below. The app and CLI share ~/.codex/config.toml.
Complete browser OAuth, choose your Arc0 workspace, and review access. If authentication does not start, run codex mcp login arc0.
Check codex mcp list, then open a new Codex chat. Inspect an existing arc0 entry before changing it.

codex mcp add arc0 --url https://api.arc0.ai/mcp

Full MCP setup and troubleshooting

All apps for OpenAI Codex

Mailgun with Cursor

Remote MCP setup

Add Arc0 in your client’s remote MCP settings using the server URL below.
Choose OAuth, sign in to Arc0, select the intended workspace and review access.
Confirm the server is connected and start with an allowed read. These are generic remote-MCP steps; consult your client’s settings for its current interface.

https://api.arc0.ai/mcp

Full MCP setup and troubleshooting

All apps for Cursor

Mailgun with VS Code

Remote MCP setup

Add a remote HTTP MCP server named Arc0 using the URL below.
Use OAuth and finish Arc0 sign-in, workspace selection and consent.
Confirm discovery succeeds before requesting a read. These are generic remote-MCP steps; client UI and availability may differ.

https://api.arc0.ai/mcp

Full MCP setup and troubleshooting

Mailgun with Any MCP client

Streamable HTTP

Use a client that supports remote MCP over Streamable HTTP. Add the server URL below and choose OAuth.
For a client without OAuth, use a self-bound API key with execute permission in the X-API-Key header. Store it in secret storage or an environment variable, outside source control. Never send both an API key and an OAuth bearer token.
Use the MCP clients guide for the SDK transport example and Embedded identity for business-managed end users.

https://api.arc0.ai/mcp

Full MCP setup and troubleshooting

After setup, ask your agent to find an allowed read action, load its schema, and execute it on the intended account. Check Activity for the receipt. A connected MCP client alone does not confirm a successful provider call.

06 · RELATED

More email apps.

GmailEarly access · 4 actions

OutlookEarly access · 6 actions

BounceBanEarly access · 6 actions

MillionVerifierEarly access · 2 actions

SendGridEarly access · 10 actions

ResendEarly access · 10 actions

PostmarkEarly access · 7 actions

HunterEarly access · 9 actions

ALL EMAIL APPS →

07 · FAQ

Mailgun and Arc0, answered.

Q01

Does Mailgun work with Claude Desktop and Claude Code?

Yes, after early access is enabled for your organization and you connect the intended account. Use Arc0’s remote MCP endpoint with OAuth. Claude Code has a documented registration command; Desktop uses the generic remote-client setup.

Q02

Can I use Mailgun with OpenAI Codex, ChatGPT and Cursor?

Yes, after early access is enabled for your organization and you connect the intended account. Codex and ChatGPT have setup instructions in Arc0’s MCP clients guide. Cursor uses the generic remote-MCP steps. Tool access remains scoped to the authorized identity.

Q03

Is this the official Mailgun MCP server?

This is Arc0’s integration page, not a claim of an official Mailgun server. Arc0 adds a shared connection, policy and audit experience across apps. Consult Mailgun for its own current MCP offerings.

Q04

Which Mailgun actions are supported?

9 registry-defined actions: 8 read, 1 write and 0 destructive. Provider permissions, access enablement and Arc0 policy determine what can execute.

Q05

Which permissions does Mailgun need?

Q06

Can I restrict writes in Mailgun?

You can deny write and destructive actions or require approval. Provider scopes and Arc0 action policies are separate controls; a policy does not grant additional provider permissions.

Q07

What does Mailgun through Arc0 cost?

See Arc0 pricing for current connectivity plans. The provider may require its own subscription or charge per request. Arc0 plan allowances do not make third-party data or paid actions free.

Get started

Request Mailgun access.

Mailgun MCP server: 9 actions including list domains, get domain, send email. Request early access through Arc0.

Request early access Browse all apps →

Free to build · MCP + REST · Audit log on every plan

Mailgun and its logo are trademarks of their respective owners. Arc0 is not affiliated with or endorsed by Mailgun.