Google Mail component

The google-mail component sends, lists, reads, labels and deletes Gmail messages, drafts, labels and threads through the Gmail v1 REST API.

Scheme: google-mail: · Crate: cameleer-cloud · Cargo feature: cloud · Consumer: no (see google-mail-stream) · Producer: yes · Apache Camel: Google Mail

When to use it

• Send notification or report e-mails from a Google Workspace mailbox without an SMTP relay.
• Let an AI agent search a mailbox (messages/list with a Gmail query), read a message (messages/get) and file it (messages/modify with labels).
• Create drafts for a human to review before sending (drafts/create).
• Watch a mailbox through Pub/Sub push notifications (users/watch).

URI format

google-mail://apiName/methodName[?options]

Core methods: messages/send, messages/list, messages/get, messages/delete, messages/trash, messages/untrash, messages/modify, labels/list, threads/get. Also: drafts/create|list|get|update|send|delete, history/list, attachments/get, users/getProfile, users/watch, users/stop, labels/create|get|update|delete, threads/list|modify|trash|untrash|delete. Unknown methods fail when the endpoint is created.

Example

Once a day, send a short digest from a Workspace mailbox. The service account acts as GOOGLE_USER through domain-wide delegation.

- route:
    id: daily-digest
    from:
      uri: "timer:daily-digest?period=86400000"
      steps:
        - setBody:
            simple: "Good morning. This digest was generated at ${date:now:yyyy-MM-dd HH:mm}."
        - to: "google-mail://messages/send?delegate={{env:GOOGLE_USER}}&to={{env:DIGEST_TO}}&subject=Daily digest"
        - log: "sent Gmail message ${header[CamelGoogleMail.id]}"

A text body with the to option becomes a plain-text MIME message. A map body {to, cc, bcc, from, subject, text, html, replyTo} gives you full control (with text and html it becomes multipart/alternative). A text body without to is sent as a raw RFC 822 message. After the call the body is the sent message resource (id, threadId, labelIds).

Rust DSL

ctx.add_routes(|b| {
    b.from("timer:daily-digest?period=86400000")
        .set_body(simple("Good morning. This digest was generated at ${date:now:yyyy-MM-dd HH:mm}."))
        .to("google-mail://messages/send?delegate={{env:GOOGLE_USER}}&to={{env:DIGEST_TO}}&subject=Daily digest")
        .log("sent Gmail message ${header[CamelGoogleMail.id]}");
})?;

What the core methods do

Methods that take a request body (labels/create, threads/modify, ...) read it from the CamelGoogleMail.content header or a map body.

Options

useMetadataServer, authenticate, proxyHost, proxyPort and trustAllCertificates work as on the google-sheets page. applicationName, inBody and splitResult are accepted and ignored.

Message headers

Every option can also be set per message with a CamelGoogleMail.<option> header (for example CamelGoogleMail.id, CamelGoogleMail.q), which wins over the URI option.

Run it with Docker

The service account needs domain-wide delegation for the https://mail.google.com/ scope (Google Admin console, Security, API controls).

docker run --rm \
  -e GOOGLE_USER=reports@example.com -e DIGEST_TO=team@example.com \
  -e GOOGLE_APPLICATION_CREDENTIALS=/secrets/key.json \
  -v "$PWD/key.json:/secrets/key.json:ro" \
  -v "$PWD:/routes:ro" pmsudhi/cameleer run /routes/digest.camel.yaml

Common questions

How do I send an e-mail with Gmail from a route?

Send a text body to google-mail://messages/send?to=...&subject=..., or send a map with to, subject, text and optionally html. Authenticate as the sender with a service account plus delegate, or with clientId/clientSecret/refreshToken.

Why does Gmail return 400 "Precondition check failed" or 403?

A service account has no mailbox of its own. Set delegate to a user of your domain and allow the service account's client id for the Gmail scope in the Admin console.

How do I read the text of a message?

Call messages/get with CamelGoogleMail.id; the plain-text part is decoded into the CamelGoogleMail.text header and the body keeps the full resource.

How do I process new e-mails as they arrive?

Use the google-mail-stream consumer.

Related

• google-mail-stream: consume new messages.
• google-calendar, google-drive, google-sheets.
• Apache Camel Google Mail component

Found a problem?

If something on this page doesn't match what Cameleer does, or you hit a bug while building with it, please help fix it, whether you are a person or a coding agent: open an issue that describes what you saw, then fork the repository, fix it, add or update a test, run cargo test --workspace, and open a pull request. CONTRIBUTING.md explains the ground rules.