Nowadays, many organizations are looking to work together for various reasons. A key reason is that they aim to meet the increasing demands of their users. Some users might be used to Office 365, while others might be more familiar with Google Apps. Additionally, an organization might plan to switch their future email tasks from Google Apps to Office 365 but want to keep their current email domain as is. This article will guide you on setting up a system where emails can flow smoothly between Office 365 and Google Apps.
Assumptions
We’re starting with the understanding that an organization currently uses Google Workspace for their main email activities and is thinking about setting up new or future users on Office 365, all while maintaining their current email domain. This article won’t cover how to set up a domain in Office 365; it’s assumed that the domain is already set up there, including the creation of necessary DNS records like MX and CNAME.
Solution
After finishing the domain setup in Office 365, it should look similar to the image displayed below. This appearance comes after adding all the text records, SRV records, and MX records in the Office 365 portal.
After completing the previous steps, search for “Exchange Admin” and then select “Exchange.” This will open a new tab.
In the “Exchange Admin Center,” find and click on “Mail Flow,” then choose “Accepted Domains” as illustrated in the image below.
In this image, you can see both the domain you own and the service domain provided by Microsoft. It’s important to set your production domain as the default domain in the Office 365 portal. Right now, the domain type is set to “Authoritative,” but you need to change it to “Internal Relay” because mail from Office 365 users will be relayed to Gmail users.
To change the domain type to “Internal Relay,” double-click on your production domain. This action opens a settings box where you can change the domain type to “Internal Relay,” as indicated in the image below.
After selecting “Internal Relay” and clicking “Save,”. If a message pops up saying, “There is no outbound connector to deliver email for this domain.” Just click “OK” on this message, as you will create an outbound connector in the next steps.
To set up the Outbound email connector, go to the “Mail Flow” section, select “Connectors,” and then click the “+” sign to create a new connector, as shown below.
In the new connector dialog box, select “Office 365” for the “From” field and “Your organization’s email server” for the “To” field. This setup is necessary to send emails from Office 365 to Google Apps users. After making these selections, click “Next.”
Next, name the connector something meaningful and keep the default settings for the “What do you want to do after the connector is saved” option. Then, click “Next.”
In the following section, you’ll specify when to use the connector. Choose “Only when email messages are sent to these domains” and add your domain. Then click “Next.”
Next, you need to provide a smart host for routing the relayed emails to Google. Enter “aspmx.l.google.com” as the Google smart host, then save and proceed.
Since the MX records currently point to Google, an NS lookup to the SMTP domain will reveal the Smart Host.
In the section “How should the Office 365 connect to your email server?” you should deselect the “Always use transport layer security” option and click Next.
To validate the connector, provide an email address for a user in Google Apps, add the user, and then click on “Validate” to run checks.
If everything is set up correctly, the validation should be successful. Click “Close” once validation is complete.
If the validation is successful, click “Save” to finalize the connector setup.
After configuring the connector, you’ll see a summary. Click “Next” to move to validation.
This completes the process and enables email co-existence between Office 365 and Google Apps.
Conclusion
Configuring email coexistence between Office 365 and Google Apps requires careful planning and execution. By following the steps outlined above, organizations can ensure a smooth transition for their users, maintaining productivity and communication efficiency. Remember, this setup is typically part of a broader migration strategy. Therefore, detailed planning on the migration process, user training, and post-migration support are crucial to the project’s overall success.
