Configuring Coexistence with Google Workspace

Split Delivery

When you configure a domain with Zoho Mail, you will point the MX records to Zoho's designated MX values. This will ensure that any emails that your domain receives are directed to Zoho Mail's servers. But in case you want your emails to be delivered to a different server, despite using Zoho Mail, you can configure it in the Admin Console.

Split Delivery can be set up when a set of your domain's accounts exist in Zoho Mail, and the rest of the accounts exist in Google Workspace. So when an account that exists in Zoho receives an email, the email will be received at the Zoho servers. In case the account does not exist in Zoho, and instead, in Google Workspace, the email will be routed to the destination Google Workspace that you have mentioned. This way you will get the benefits of Zoho Mail for one set of users, while the rest of them do not miss out on the features of Google Workspace.

When you configure split delivery, the server to which your MX Records are pointed will be the primary server, and the other server will be the secondary server. For example, if Zoho Mail's MX records are added to your DNS provider, Zoho Mail will be your primary server, and the split delivery configuration has to be set up here.

Prerequisites to configure Split Delivery

1. It is recommended that you create your domain's groups or distribution lists in the server to which your MX records are pointed. If your MX records point to Zoho Mail, ensure that your groups are created in Zoho Mail.
2. While configuring SPF for the domain, the SPF record should include both Zoho Mail and Google Workspace records to authorize emails from both IPs. The SPF record that includes both Zoho Mail and Google Workspace values should be mentioned as:
   v=spf1 include:_spf.google.com include:zoho.com ~all
3. Any emails addressed to email addresses that are not configured in Zoho, will be routed to the Google Workspace server. In some cases, there could be spam or other emails that are sent to unknown email addresses. So if the account to which it is addressed is not configured in Google Workspace, the emails could be rejected or a routing failure could occur.
   To avoid this, a catch-all account can be configured in Google Workspace so that these emails do not go missing.
4. It is highly recommended that Zoho's routing IP address is whitelisted in the Google Workspace account. Since all the routed emails will be sent via the same IP address, whitelisting will avoid the chance of emails being identified as spam and will also avoid the rate-limiting of emails.

Split delivery should be set up in Zoho only after all the above requisites are addressed, and before the MX records are pointed to Zoho servers.

Configuring Split Delivery with G Suite

There are two ways in which your organization can coexist with Google Workspace.

You can set up Zoho Mail as your primary server, and configure the email routing to your Google Workspace account, in the Zoho Mail Control Panel. In this case, the MX Records need to be pointed to Zoho Mail's servers.

Instead, if you want to use Google Workspace as your primary server, you need to configure routing in Google Workspace, and set it up such that emails are routed to Zoho Mail. Here, the MX Records should be pointed to Google's servers.

Zoho Mail as the primary server

If you want Zoho Mail as the primary server, follow the below configuration instructions in Zoho Mail.

1. Login to the Zoho Mail Admin Console
2. Go to the Email Routing section
3. If you have multiple domains configured with Zoho Mail, select the domain for which you want to configure routing from the Domain to enable delivery options dropdown
4. In the Destination to route emails field, you can either enter the Google Workspace specific MX record value with the least priority or the name of the domain to which you want to route these emails. 
   1. If the domain for which you are configuring routing is the same as the domain to which you'd like to route emails, enter the MX record ASPMX.L.GOOGLE.COM. in this field.
   2. If you are routing the emails to a different domain, enter the name of that domain in this field.
5. In the Email Delivery options dropdown, select Split Delivery
6. Enter a Verification Email Address. This email address should be a part of the domain for which you are configuring routing, but it should be an account that exists in Google Workspace. Ideally, your Google Workspace account's super admin address can be used here.
7. The Change SMTP envelope is used when you want the emails to be delivered to the destination that you have specified in the settings. Sometimes, you might add a different domain name in the destination field (for example, destinationdomain.com). The domain for which you are configuring routing might be mydomain.com. If this option is enabled, the email will be sent to user@destinationdomain.com, while it is actually sent to user@mydomain.com
8. If you enable the Send bounce when the mail to the destination fails, a bounce email will be sent to the email sender if email delivery fails.
9. Turn on the Status for Advanced Delivery option.
10. The Routing for group members option has to be turned on only if you have public groups, in which some users exist in Zoho Mail and the rest of the group members exist in Google Workspace. In that case, if an email to the group has to be delivered to group members who exist on Google Workspace as well, this option has to be turned on.

Once these configurations are done, emails will be delivered to Zoho Mail for accounts that exist here and will be routed to Google Workspace for users that exist here.

Google Workspace as the primary server

If you want to set up Google Workplace as the primary server, follow Google Workspace's instructions to set up routing from the Route messages with a split delivery section on this help page.

In the hostname field, you can either enter the Zoho Mail specific MX record value with the least priority or the name of the domain to which you want to route these emails. 

1. If the domain for which you are configuring routing is the same as the domain to which you'd like to route emails, enter the MX record mx.zoho.com in this field.
2. If you are routing the emails to a different domain, enter the name of that domain in this field. In this case, select the Perform MX lookup on the host checkbox.

We recommend that you whitelist the Google Workspace's routing IP address in Zoho Mail's Admin Console. Since all routed emails are transmitted via the same IP address, whitelisting will avoid the chance of emails being identified as spam and will also avoid the rate-limiting of emails.

Once these configurations are done, emails will be delivered to Google Workspace for accounts that exist there and will be routed to Zoho Mail for users that exist here.