How To Configure Google GSuite Split Delivery for cPanel?

We host our client’s on WHM/cPanel server and are currently switchting to Google G Suite.

90% of the email addresses on this domain are to be migrated to Google gSuite, but the remaining 10% will remain on cPanel (need not to be migrated).

Google faciliates this by offering split delivery. Below is a summary of the implementation steps:

Part I: Google GSuite Configurations:

1. In your GSUITE admin console, go to Apps -> Gsuite -> Gmail
2. Under Gmail go to Hosts and add a mail route for a domain (Follow this google link here: https://support.google.com/a/answer/2614757).
3. Next, go to Advanced Settings -> General Settings – > Routing and click on Configure.

Settings in your Routing should be as follows:

• Name of your route “My Other Mails” you can give the route any name you will easily remember
• Message to affect: inbound, Internal – receiving
• Route – Change route : Add the mail route you had configured in Step 2.
• click on Show options
• Accounts type to affect: Unrecognized / Catch-all
• Save

4. Under Default Routing, add a new rule:

• Specify envelope receipts to match, choose Pattern match
     Regexp:   \w+@gapps.yourdomain.com

• Under Envelope Receipt -> check on change envelope recipient then choose Replace Domain and enter your primary domain name.

• Under Options, check on perform this action on non-recognized and recognized addresses.
• Click Save.

5. By now, you had already configured your MX records pointing to GSuite.
6. Your DKIM and SPF must reflect both servers if you’re to avoid authentication email errors when trying to send to emails remaining in cpanel (non-gmail). See error below:

Part II: WHM/cPanel Configurations:

7. Alternatively you can use Email Deliverability tool in Cpanel to help you configure your authentications right.
8. Root domain (yourdomain.com) must have MX records pointing to Google’s MX servers;
    
9. There must be a subdomain CNAME (gapps. yourdomain.com) as alias of root domain (yourdomain.com), this will be used to deliver mail sent through cPanel or its SMTP.
   In Cpanel go to Domains -> Aliases
   After creating your alias domain, click on manage redirection to point the alias to primary domain “yourdomain.com”.
10. NOTE:

• You must also create a domain alias on Google gSuite (under Account->Domains->Manage Domains).
• This required setting up the alias and pointing it to yourdomain.com to be able to put the file that Google gSuite wanted in place to verify the domain (gapps. yourdomain.com) belonged to us.
  Instructions are given by Google when trying to add a domain alias. (https://support.google.com/a/answer/7502379?hl=en)

11. In WHM/cPanel Edit DNS Zone for your primary domain,

• Make your primary domain MX record to point to google GSuite mail servers
• Set email routing as ‘Local Mail Exchanger’ :

12. In WHM/cPanel Edit DNS Zone for alias domain “gapps.yourdomain.com“,

• Make your alias domain MX record to point to google GSuite mail servers
• Set email routing as “Remote Mail Exchanger“.

12. In WHM/cPanel, under Email Forwarders add a Domain forwarder from your primary domain “yourdomain.com” to “gapps.yourdomain.com“

These are the neccessary steps to successfully implement split delivery. Enjoy!