JMAP Email
Email management via JMAP — mailboxes, messages, identities, and Sieve scripts
Install
Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).
ghcr.io/mikluko/jmap-mcp:0.10.0claude mcp add jmap-email -e 'JMAP_SESSION_URL=<JMAP_SESSION_URL>' -e 'JMAP_AUTH_TOKEN=<your jmap_auth_token>' -- docker run -i --rm ghcr.io/mikluko/jmap-mcp:0.10.0{
"mcpServers": {
"jmap-email": {
"command": "docker",
"args": [
"run",
"-i",
"--rm",
"ghcr.io/mikluko/jmap-mcp:0.10.0"
],
"env": {
"JMAP_SESSION_URL": "<JMAP_SESSION_URL>",
"JMAP_AUTH_TOKEN": "<your jmap_auth_token>"
}
}
}
}Environment variables
JMAP_SESSION_URLrequired JMAP session endpoint URL (e.g. https://api.fastmail.com/jmap/session)JMAP_AUTH_TOKENrequired secret JMAP bearer token for authentication
Documentation
From the project's README on GitHub, refreshed weekly. Links open on GitHub.
jmap-mcp
MCP server exposing JMAP email and Sieve script operations as tools.
Built with the Go MCP SDK (go-sdk) and go-jmap library.
Tools
Tools map closely to JMAP methods. Email mutation tools provide structured convenience wrappers over Email/set patches.
Mailbox (RFC 8621)
| Tool | JMAP Method | Description |
|---|---|---|
mailbox_get | Mailbox/get | Get mailboxes by ID, or list all |
mailbox_set | Mailbox/set | Create, update, or destroy mailboxes |
Email (RFC 8621)
| Tool | JMAP Method | Description |
|---|---|---|
email_query | Email/query | Search emails with filters, returns IDs and total count |
email_get | Email/get | Get full content of emails by ID |
email_create | Email/set | Create a new email draft in the Drafts mailbox |
email_move | Email/set | Move emails to a different mailbox |
email_flag | Email/set | Set or remove flags (seen, flagged, answered, draft) |
email_delete | Email/set | Delete emails (move to Trash or permanently destroy) |
email_attachment_url | Blob download | Signed URL streaming an attachment, expires in 30 s (HTTP mode only) |
Identity
| Tool | JMAP Method | Description |
|---|---|---|
identity_get | Identity/get | List sender identities (email addresses) |
Submission (feature-gated)
| Tool | JMAP Method | Description |
|---|---|---|
email_submission_set | EmailSubmission/set | Submit a draft for delivery (requires -enable-send) |
Sieve Scripts (RFC 9661, feature-gated)
| Tool | JMAP Method | Description |
|---|---|---|
sieve_get | SieveScript/get | List all scripts, or get one with full content (requires -enable-sieve) |
sieve_set | SieveScript/set | Create, update, or destroy Sieve scripts (requires -enable-sieve) |
sieve_validate | SieveScript/validate | Validate a Sieve script without saving (requires -enable-sieve) |
Configuration
| Env var | Required | Description |
|---|---|---|
JMAP_SESSION_URL | always | JMAP session endpoint (e.g. https://api.fastmail.com/jmap/session) |
JMAP_AUTH_TOKEN | stdio mode | Bearer token for JMAP authentication |
ATTACHMENT_URL_SECRET | no | Secret sealing signed attachment URLs; set for multi-replica deployments (default: random per-process key) |
| Flag | Default | Description |
|---|---|---|
-mode | stdio | Server mode: stdio or http |
-listen | :8080 | HTTP listen address (http mode only) |
-enable-send | false | Enable the email_submission_set tool (off by default) |
-enable-sieve | false | Enable Sieve script tools (off by default, requires JMAP server support) |
-external-url | derived | External base URL for signed attachment links; default derives from the request (X-Forwarded-Proto/X-Forwarded-Host aware) |
In HTTP mode, the token can be passed per-request via Authorization: Bearer <token> header or jmap_token query parameter (query parameter takes precedence).
In HTTP mode, email_attachment_url returns a link served from /attachments/ that expires 30 seconds after issuance. The link is an AES-GCM sealed capability: it embeds the JMAP token, account, and blob IDs, so the endpoint streams the attachment from the JMAP server without any additional authentication and stores nothing on disk.
Installation
Kubernetes (Helm)
helm install jmap-mcp oci://ghcr.io/mikluko/helm-charts/jmap-mcp \
--version 0.1.0 \
--set jmap.sessionURL="https://api.fastmail.com/jmap/session"In HTTP mode, JMAP auth tokens are passed per-request via Authorization: Bearer header or ?jmap_token= query parameter — no static tokens are stored in the cluster.
Binary
go install github.com/mikluko/jmap-mcp@latestFrom source
git clone https://github.com/mikluko/jmap-mcp.git
cd jmap-mcp
make installUsage
# stdio mode (default)
export JMAP_SESSION_URL=https://api.fastmail.com/jmap/session
export JMAP_AUTH_TOKEN=your-token
./jmap-mcp
# HTTP mode
./jmap-mcp -mode http -listen :8080Build
make build # Build and push container image + Helm chart
make image # Build and push container image with ko
make package # Package and push Helm chart to OCI registry
make test # Run tests
make install # Install binary locallyReferences
- RFC 8620 — JMAP Core
- RFC 8621 — JMAP Mail
- RFC 9425 — JMAP Sieve Scripts
- MCP Specification
Frequently asked questions
What is JMAP Email?
Email management via JMAP — mailboxes, messages, identities, and Sieve scripts
How do I install JMAP Email?
It runs on your machine. In Claude Code: claude mcp add jmap-email -e 'JMAP_SESSION_URL=<JMAP_SESSION_URL>' -e 'JMAP_AUTH_TOKEN=<your jmap_auth_token>' -- docker run -i --rm ghcr.io/mikluko/jmap-mcp:0.10.0. For other clients, paste the JSON configuration from this page into their MCP settings.
Does JMAP Email need an API key?
Yes. It expects JMAP_SESSION_URL, JMAP_AUTH_TOKEN, which you set in its configuration.
Is JMAP Email open source?
Its code is public on GitHub, but the repository does not declare a standard license.
Who maintains JMAP Email?
It is published by mikluko. AI.tn lists it but does not maintain or endorse it.
From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.