← All installation guides High Security Email Integrations

Set up High Security email on Google Workspace and Gmail API

Use a trusted application to create the complete MIME message and send it through the Gmail API; a Gmail web signature cannot call the VEM API.

GAPI
Recommended methodServer-side per-message API
Trusted-server integration

Create, bind and deliver each message code safely

  1. 1

    Use a server application

    High Security requires an approved server application with Gmail API authorization. A Gmail web, mobile or desktop signature can show only the Low Security linked seal image.

  2. 2

    Build the final MIME identity

    Create the complete RFC 2822 MIME message in the application and assign a unique Message-ID using the verified sender domain before calling VerifySeal.

  3. 3

    Request and insert the code

    Request the VEM code from the trusted server, add message_code.header to the MIME headers, and append the returned footer to every body alternative.

  4. 4

    Send the raw MIME message

    Base64url-encode the completed MIME message and submit it with the Gmail API messages.send method. Do not modify the body or identity after the VEM request.

  5. 5

    Confirm Google preserved the identity

    Retrieve or externally receive the sent message and inspect the original source. The final Message-ID must exactly match the value bound to the VEM code.

  6. 6

    Check Workspace authentication

    Confirm the received message has the VEM header/footer and aligned DKIM/DMARC passes. If Google replaces Message-ID in your flow, the integration is not compatible without a different gateway.

Open Gmail API sending documentation ↗
High Security still requires domain authentication

A VEM code does not replace SPF, DKIM or DMARC

The sender domain must continue to publish a valid SPF record, the selected DKIM key and a DMARC policy. VerifySeal automatically rechecks these records according to the administrator schedule. For High Security messages, DKIM must cover the final Message-ID, VEM header and completed body.

  • SPF authorizes sending services
  • DKIM verifies the signed message domain
  • DMARC publishes the domain policy
Testing checklist

Confirm the installation is working

01

Message-ID

The exact final Message-ID is created before the API request and matches the sent email.

02

VEM code

The returned header and footer are present and the public verification link opens.

03

DKIM last

The receiving service reports an aligned DKIM and DMARC pass after all content was inserted.

04

Revocation

Revoking the test code immediately changes its public status.

Platform notes
  • Normal Gmail signatures and routing-rule footers cannot safely store a VerifySeal API key or request a unique code for each final Message-ID.
  • Test the exact Gmail API sending method and account configuration used in production.