It was intense 3 days of googling and trying to make my client’s email work since some users had been configured on google and others left on the Cpanel server for reason best known by the client.

STAGE 1

Make sure you configure split delivery very well as Google advises here https://support.google.com/a/answer/2685650. If you have difficulty understanding google’s configs here is short version of it all.

  1. In your GSUITE admin console, go to Apps -> Gsuite (core services) -> Gmail
  2. Under Gmail go to Hosts then Add a mail route for a domain ( Follow the google link here https://support.google.com/a/answer/2614757 ).
  3. Move to Advanced Settings -> General Settings - > Routing and click on configureHowto configure Gsuite Split delivery work in CPANEL
  4. 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


  5. Under Default routing Tab
    Howto configure Gsuite Split delivery work in CPANEL

    Click on ADD SETTING
    - Specify envelope receipts to match choose Pattern match
       Regexp:   \This email address is being protected from spambots. You need JavaScript enabled to view it.
    Howto configure Gsuite Split delivery work in CPANEL
    - Envelope Receipt
    -> click on change envelope recipient then choose -> This email address is being protected from spambots. You need JavaScript enabled to view it.
    Howto configure Gsuite Split delivery work in CPANEL
    - Options
    -> perform this action on non-recognized and recognized addresses

Now that your done with GSUITE side, its time to get into your Cpanel.

STAGE 2
NOTE:

    • Remember that you had already configured your MX records pointing to GSuite.
    • 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

Alternatively you can use Email Deliverability tool in Cpanel to help you configure your authentications right.

      1. Root domain (yourdomain.com) must have MX records pointing to Google's MX servers;

      2. 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 below same area click on manage redirection to point the alias to primary domain “yourdomain.com” .
        Howto configure Gsuite Split delivery work in CPANEL


        Howto configure Gsuite Split delivery work in CPANEL
        NOTE:
        - This must also be set as a domain alias on Google Apps.
        - This required setting up the alias and pointing it to yourdomain.com to be able to put the file that Google Apps 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)

      3. Make your primary domain MX record to point to google apps mail servers and set as 'Local Mail Exchanger'
        Howto configure Gsuite Split delivery work in CPANEL
      4. Make alias domain “gapps.yourdomain.com” set as ‘Remote Mail Exchanger’
      5. Under Email Forwarders add a Domain forwarder from your primary domain “yourdomain.com” to “gapps.yourdomain.com
        Howto configure Gsuite Split delivery work in CPANEL
        Add Domain Forwarder
        Howto configure Gsuite Split delivery work in CPANEL

        Add a New Domain Forwarder
        Howto configure Gsuite Split delivery work in CPANEL

If you configure those two stages very well, you will surely enjoy gsuite split delivery.

Good luck.