If your organization uses Microsoft Exchange or another SMTP service or server, you can set up the SMTP relay service to route outgoing mail through Google. You can use it to:
- Filter messages for spam and viruses before they reach external recipients
- Apply email security and advanced Gmail settings to outgoing messages
Before you begin
Review server configuration
- If you’re using TLS encryption, configure your on-premise mail server to point to https://smtp-relay.gmail.com/ on port 587.
- If you’re not using TLS encryption, configure your on-premise server to point to https://smtp-relay.gmail.com/ on port 25, 465, or 587. Without TLS encryption, you can't use SMTP authentication and must use IP address authentication.
Step 1: Set up SMTP relay in your Google Admin console
- If your current account might not have permission to do these steps, to continue, make sure you're signed in to an administrator account.
- In the Admin console, go to Menu > Apps> Google Workspace>Gmail>Routing.
You can add, edit, and delete the SMTP relay service setting at the top-level organization only. You can view the setting at the child organizational unit level.
- Scroll to SMTP relay service and click Configure. If the setting is already configured, click Edit or Add another.
- Enter a name for the setting and set up the following options:
What to do
Choose an option:
Check one or both boxes to set an authentication method:
If you select the specified IP addresses option:
(Optional) To require TLS for connections between your server and Google, check the Require TLS encryption box.
Important: If your email server doesn't support TLS and you check this box, messages not sent over an encrypted TLS connection are rejected.
Changes can take up to 24 hours but typically happen more quickly.