Google Workspace Split Delivery

If you use Google Workspace for your primary mailboxes but want ImprovMX to handle catch-all addresses or specific aliases, you can configure split delivery. Google Workspace will handle known users while forwarding unrecognized recipients to ImprovMX.

Prerequisites

• Full admin access to your Google Workspace account
• Your domain's MX records pointing to Google Workspace with higher priority than ImprovMX
• Recommended: Disable Strict MX Verification in Google Admin to avoid alerts about lower-priority MX records

Step 1: Add the ImprovMX Mail Route

First, create a mail route in Google Admin Console that points to ImprovMX servers.

1. Open the Google Admin Console
2. Navigate to Apps > Google Workspace > Gmail > Hosts
3. Click Add Route
4. Configure the mail route with these settings:
   • Name: ImprovMX
   • Single host / Multiple hosts: Select Multiple Hosts
   • Primary host: mx1.improvmx.com, Port: 25, Load: 50%
   • Secondary host: mx2.improvmx.com, Port: 25, Load: 50%
5. Under Options, enable the following:
   • Require TLS
   • Require CA signed certificate
   • Validate certificate hostname
6. Click Test TLS Connection to verify, then Save

Step 2: Set Up Split Delivery Routing Rule

Next, create a routing rule that forwards unrecognized addresses to the ImprovMX mail route.

1. In Google Admin Console, go to Apps > Google Workspace > Gmail > Default Routing
2. Click Add Setting or Configure
3. Configure the routing rule:
   • Name: ImprovMX Routing
4. Under Email messages to affect:
   • Enable: Inbound and Internal - receiving
   • Disable: Outbound and Internal - sending
5. Under For the above types of messages, do the following:
   • Select Change route
   • Choose the ImprovMX route you created
   • Disable Spam rerouting
   • Disable Suppress bounces from this recipient
6. Under Account types to affect:
   • Select only Unrecognised / Catch-all
7. Click Save

Step 3: Configure ImprovMX Aliases

In your ImprovMX dashboard, create the aliases you want to forward. For example:

• info@yourdomain.com → your-personal@gmail.com
• * (catch-all) → catchall@gmail.com

Step 4: Verify the Configuration

After saving your settings:

1. Send a test email to a Google Workspace user — it should be delivered to their mailbox
2. Send a test email to an ImprovMX alias — it should be forwarded to your configured destination

Note: Google Workspace will attempt delivery to its users first. Only emails to addresses not recognized in Google Workspace will be forwarded to ImprovMX.

SPF Configuration

When using both services, combine the SPF records into a single TXT record:

v=spf1 include:_spf.google.com include:spf.improvmx.com ~all

See our guide on combining SPF records for more details.