100% Inbox Delivery

Home › Blog › How to Gmail smtp relay server

How to Gmail smtp relay server

Published October 16, 2024 · Updated July 18, 2026 · SMTP & Deliverability

For organisations on Google Workspace, the Gmail SMTP relay server lets your devices and apps route mail through Google at higher volume than a single Gmail account allows. It is designed for internal systems — printers, scanners, line-of-business apps — that need to send on behalf of your domain. Here is how it works.

What the Workspace relay server is

Unlike sending as one user through smtp.gmail.com, the relay server (smtp-relay.gmail.com) is authorised at the domain level by a Workspace admin. It supports higher throughput and lets multiple systems send under your organisation's umbrella.

How to enable it

  1. In the Google Admin console, open Apps → Gmail → Routing and configure the SMTP relay service.
  2. Authorise your sending IP addresses (or require authentication).
  3. Point devices and apps at smtp-relay.gmail.com on port 587.
  4. Confirm SPF and DKIM include Google so mail is trusted.
Still a business tool: The Workspace relay lifts the ceiling, but it is built for internal and business mail — not marketing campaigns. Bulk sends still belong on a dedicated SMTP.
Related reading: Relay gmail smtp · Freeware smtp relay · test your email deliverability
For real volume

A dedicated SMTP relay server

Dedicated IP, unlimited sending, and automatic authentication — for the marketing and bulk mail Workspace isn't built to carry. From $39.99/mo.

Get a dedicated SMTP server →View pricing

Frequently asked questions

What is the Gmail SMTP relay server?

smtp-relay.gmail.com, the Google Workspace service that lets your domain's devices and apps relay mail at higher volume, authorised by an admin.

How is it different from smtp.gmail.com?

The relay is domain-authorised and supports higher throughput and multiple senders; smtp.gmail.com sends as a single user with lower caps.

Can I use it for marketing email?

It is not intended for marketing blasts. Use a dedicated SMTP with its own IP and no caps for bulk campaigns.