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Google Workspace Server-Side Email Signatures: Gmail Routing

Configure a Gmail send route, SMTP relay and content compliance rule so Google Workspace signatures are appended in transit on every device and client.

WiseStamp for IT › Google Workspace › Step 5 of 12 — Server-Side Deployment

Plan requirement: Platform or Enterprise.

How it works

Outbound mail leaves Gmail, routes to the WiseStamp server-side host, gets the signature appended, and returns for delivery. Because the signature is applied in transit, it is consistent regardless of sending device or client.

Server-side can run alone or in hybrid mode with Auto-Inject — in hybrid, the server-side service only appends a signature when it doesn’t already detect a WiseStamp signature, preventing duplicates. See Setup Overview.

Prerequisites

  • Step 1 complete: Google Workspace directory connected (Connect Your Directory).

  • Google Workspace super administrator rights.

  • Access to Apps > Google Workspace > Settings for Gmail (Hosts, Routing/SMTP relay, Compliance).

  • SPF updated with include:outbound.smtp.wisestamp.net; DKIM record from WiseStamp added (see Prerequisites Checklist).

  • WiseStamp relay IP addresses ready to allowlist (see below).

  • Your routing code (provided during the WiseStamp wizard / by support).

Configuration phases

Follow the WiseStamp integration wizard, which walks you through these in order.

Phase 1 — Configure SPF

Add include:outbound.smtp.wisestamp.net to your domain’s SPF TXT record before routing mail. Details in Prerequisites Checklist.

Phase 2 — Integrate Google Workspace with WiseStamp

Complete directory integration if not already done (Connect Your Directory).

Phase 3 — Start the WiseStamp integration wizard

In WiseStamp: Integrations > Server-side for all email platforms > Connect > Google Workspace. Keep this wizard open; it provides your routing code and the connect confirmation at the end.

Phase 4 — Add a mail host (send route) in Google Admin Console

  1. Google Admin Console > Apps > Google Workspace > Settings for Gmail > Hosts.

  2. Click ADD ROUTE.

  3. Set the host to your routing code followed by .gw.smtp.wisestamp.net (e.g. <routing-code>.gw.smtp.wisestamp.net).

  4. Use port 25.

  5. Save the host.

Phase 5 — Configure the SMTP relay service

Configure the SMTP relay so Gmail accepts mail coming back from WiseStamp:

  1. In Settings for Gmail, configure the SMTP relay service.

  2. Set Allowed senders to Only addresses in my domains.

  3. Under Authentication, select Only accept mail from the specified IP addresses and add all seven WiseStamp relay addresses:

    34.121.227.57
    34.121.44.217
    34.172.57.131
    34.31.145.8
    34.132.46.63
    35.184.115.114
    35.224.208.1

  4. Under Encryption, select Require TLS encryption.

  5. Save.

All seven addresses are required. An incomplete allowlist causes Gmail to reject mail returning from WiseStamp, which presents as intermittent send failures rather than a configuration error.

Phase 6 — Configure the content compliance rule

Create the routing rule that sends outbound mail to the WiseStamp host:

  1. Settings for Gmail > Compliance > Content compliance.

  2. Create a rule that routes outbound messages to the WiseStamp server-side host (the host added in Phase 4).

  3. Save.

For the exact field-level Content Compliance rule setup, including exclusions (auto-replies/large messages), see the Server-side configuration for Google Workspace help-center article.

Phase 7 — Finish the wizard

Return to the WiseStamp wizard and click Connect.

Validation (validity check)

  1. In WiseStamp, activate your user.

  2. Send a test email and confirm the WiseStamp signature appears.

  3. Test from a non-Gmail device (mobile mail app) to confirm cross-client coverage.

  4. Check authentication results show SPF and dkim=pass (see Prerequisites Checklist, Troubleshooting Reference).

Full acceptance steps: Go-Live Checklist.

Server-side signature rules

After connecting, assign signatures by rule (Platform/Enterprise): Integrations > Server-side > Signature rules > Add rule.

  • Sender conditions: all employees / specific groups / specific employees.

  • Email type: all / new / reply.

  • Recipient conditions: all / at least one internal / all internal / at least one external / all external.

  • Priority: higher number wins when multiple rules match.

Activate with the Active toggle and confirm.

Emergency: disable routing

If outbound mail stops or is rejected, disable the compliance rule so mail bypasses WiseStamp, then contact support:

  1. Google Admin Console > Apps > Google Workspace > Settings for Gmail > Compliance.

  2. In Content compliance, find the rule you created for WiseStamp and click Disable.

While disabled, all mail bypasses WiseStamp and no server-side signature is applied. Re-enable to resume. See Troubleshooting Reference.

← Previous · Google Workspace Email Signatures: Auto-Inject into Gmail
​Next → · Google Workspace SAML SSO for Email Signature Admins

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