How to Set Up Google Workspace SMTP Settings

Google Workspace offers an SMTP relay service that allows businesses to send email securely from devices, applications, and third-party clients using Google’s servers. It’s particularly useful for organisations that need to deliver automated or transactional emails from non-Gmail systems—such as printers, scanners, CRM platforms, or custom business applications.

Unlike personal Gmail SMTP, the Workspace SMTP relay is built for business administration. It goes beyond simply sending emails and provides several key benefits:

• Centralised outbound mail – Route all email traffic through Google’s trusted servers, simplifying management for admins and ensuring consistency across the business.
• Improved deliverability – With SPF and DKIM alignment, your messages are far less likely to land in spam folders, meaning important emails like invoices or system alerts reach inboxes reliably.
• Enhanced security – Enforce TLS encryption, restrict relay use to authorised IPs or accounts, and protect against spoofing or abuse.
• Scalability and reliability – Google’s infrastructure handles high volumes without disruption, supporting business growth and continuity.

In short, SMTP relay isn’t just a technical convenience, it’s a way to maintain trust, compliance, and reliability in every email your organisation sends.

What is Google Workspace SMTP Relay?

The SMTP relay in Google Workspace routes email through Google’s secure infrastructure, giving admins control over outbound mail and ensuring it passes authentication checks.

Common use cases include:

• Transactional/system emails – Sending booking confirmations, password resets, or invoices from business apps.
• Multifunction printers/scanners – Allowing devices to send scanned files via email.
• Centralised delivery – Consolidating outbound traffic to improve deliverability and visibility.

For IT leaders, SMTP relay strengthens security, supports compliance, and reduces spam risk. And because email is business-critical, protecting that data with Google Workspace Backup ensures you’re covered against loss or accidental deletion.

Google Workspace SMTP Settings

Here are the key settings you’ll need:

How to Configure SMTP Relay in Google Admin Console

Admins can configure the relay from the Admin Console:

1. Log in to the Google Admin Console.
2. Navigate to Apps > Google Workspace > Gmail > Routing.
3. Scroll to SMTP Relay Service and click Configure.
4. Choose Allowed senders:
   • Only addresses in my domains (recommended).
   • Only registered users in my domain (tighter control).
5. Pick an authentication method:
   • Require SMTP authentication (username/password), or
   • Restrict by IP address (ideal for devices like printers).
6. Enable TLS encryption to keep messages secure and compliant.
7. Save changes and allow up to 24 hours for propagation.

Authentication & Security Best Practices

Correct configuration is important, but security policies make the difference between a safe setup and a vulnerable one.

• IP whitelisting vs. login authentication – Use IP restrictions for fixed devices, login authentication for apps and mobile tools. This balances flexibility with control.
• SPF, DKIM, and DMARC alignment – Ensures outgoing mail is validated, improving deliverability and protecting against spoofing.
• TLS enforcement – Encrypts mail in transit, supporting GDPR and ISO 27001 compliance.
• Avoid “any address” option – Restricting senders to your own domain protects your reputation and prevents abuse.
• App-specific passwords – For MFA-enabled accounts, use app passwords so you don’t compromise security when connecting apps or devices.

These practices not only harden your defences but also improve inbox placement rates and maintain compliance across your organisation.

Troubleshooting Google Workspace SMTP Relay

Even with correct settings, problems may arise. Here’s how to fix them quickly:

• Emails not sending – Verify the sender’s IP or account is authorised.
• Best port to use – Choose 587 with TLS for security and compatibility. Port 465 also works; 25 is fallback only.
• “550 SMTP error” – The sender isn’t allowed in your relay settings. Confirm allowed senders and authentication.
• Delays or throttling – Hitting daily limits (10,000 messages/domain) can cause this. Monitor usage to prioritise critical email.
• Authentication options – IP-only relay works for devices, but using authentication + TLS is safer for most cases.
• Printers/scanners – Yes, SMTP relay is the recommended way to send from these devices securely.

By addressing these common issues, you’ll keep your SMTP relay reliable and your business communications uninterrupted.

Protecting Your Workspace Email & Data: Try BackupVault Free

Setting up SMTP relay ensures email delivery, but it doesn’t protect you from data loss. Accidental deletions, insider threats, or ransomware can all put Gmail and Workspace data at risk.

That’s where Google Workspace Backup from BackupVault comes in. With daily automated backups of Gmail, Drive, Contacts, and Calendar, encrypted UK-based storage, and instant restores, it keeps your business compliant and resilient.

Explore BackupVault’s full range of cloud backup solutions and start your free trial today.