1 domain with coexist between Office 365 and Gsuite

Can we do 1 (one) domain, and then we are split all the users with some users at Office 365 and some users again at Gsuite ? The answer is yes you can.

This scenario actually on our clients currently not a common, but we can help you.

Because maybe in some organizations want to coexist due to different reasons. The major reason is that user demands more and organizations want to cater to this ever demanding user base. Some users might be familiar with Office 365 while some might be familiar with Google Apps. Also, the organization might want to move their future email workloads from a different platform like Google Apps to Office 365 while still keeping their existing email domain intact.

In this article, my scenario is that I have 1 domain abc-abc.site then I have registered the domain to CloudFlare to manage my dns. Because cloudfare is free for one site and also easy to manage for sub domains.

Here is the demo that we will cover for this demo.

Here as below the steps that i did in on my testing :

  1. Create subsciption to GSuite and validate the domain above to able send an email.

To validate it, we will update some MX record on our DNS, here as below my sample for my domain

Then after the validation done, you can test sending an email. In here i am also create 2 users Agusto@xxx.xxx and Erna@xxx.xxx

2. Create subsciption to Office 365 and validate the same domain like we did in on Gsuite

Here as below the MX that we need to insert on our DNS :

Then after the validation done, Ini here i am also create 2 users aaron@xxx.xxx and kayla@xxx.xxx

3. Once that’s done, navigate to “Exchange Admin Center” by navigating to “Admin > Exchange”. This will open up a new tab. Once in the “Exchange Admin Center” under “Mail Flow” select “Accepted Domains”

Once done, it will open up the “Accepted Domain”

In the above figure, the domain that you own and the service domain Microsoft Provides are both visible. Make sure the domain that is used in the production is set to the default domain in the Office 365 portal. Currently, the domain type is set to “Authoritative”. This must be changed to “Internal Relay” as mail will be relayed to the Gmail Mail users from Office 365 mail users.

To set the domain type to an internal relay, simply double-click the “xxx.xxx” (The production domain) domain to bring up the settings box to change the domain type to a relay as shown below

4. Now all already set up, now we need to set up the Connector.

To create the Outbound email connector, within the “Mail Flow” section select “Connectors” and click “+” sign to create a new connector as shown 

In the next section, specify when to use the connector which is created. In this scenario, this connector is needed to relay emails only when emails are sent to someone@techiewithablog.com SMTP domain (In this scenario. In your scenario the domain name will be different). Therefore, under “When do you want to use this connector?”” select, “Only when email messages are sent to these domains” and click “+” to add the respective domain that is used in the respective scenario. In this case, the domain “techiewithablog.com” is added as shown in the below . Once done click “Next”.

In the next section, a smart host needs to be provided to configure Office 365 to route the relayed emails. This is going to be the Google smart host that should be specified. Therefore, include “aspmx.l.google.com” as the Google smart host as shown below and click “Save” and “Next”.

Since the MX records are currently pointed to Google, doing an NS lookup to the SMTP domain will get you the Smart Host.

Once in the next section, for “How should the Office 365 connect to your email server?” section, deselect “Always use transport layer security option” and click Next as below

This will now run a series of validation checks against the connector by sending an email to verify the connector is working properly. If everything goes smooth, the validations progressing should be successful and the final result as shown below. Once the validation is done, click “Close” 

If the validation is successful, the validation results will be shown as successful as shown in the below. Once done, click “Save” so that the connector is now ready to relay emails to Office 365 and Google Apps.

5. Done

This should now enable email co-existence between the two platforms.

If you need more futher to know about this feature, or need a help to migrate or setup like this scenario. We are Infinys team able help you. Please go to this site https://infinyscloud.com/en/help and we will soon to contact you.

Reference Article(s) : https://social.technet.microsoft.com/wiki/contents/articles/36118.configure-email-coexistence-between-office-365-google-apps.aspx


https://mymicrosoftexchange.wordpress.com/2015/06/21/how-to-configure-mail-flow-coexistence-between-gapps-and-o365-using-internal-relay-domains-and-mail-users

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