Is it possible to configure\merge multiple Office 365 tenants to Sync with single AD Forest and use a same SMTP address??

Question

Is it possible to configure\merge multiple Office 365 tenants to Sync with single AD Forest and use a same SMTP address??

Client has two companies under one roof, on one domain. Recently went to Office365 but did it as two tenants due to billing separation and purchased  two separate office 365 business accounts, but have a handful of employees on both tenants. All users using the one Exchange 2013 and one Lync 2013 Environment with @company.com emailaddress. They're using Lync and room resources in Exchange for their conference rooms.  I would like to get them on Lync online, using room resources and syncing passwords with AADSync.

Both Companys want to keeps there own tenants, reason because of the simple math involving splitting the subscriptions and administration,

Everyone would be on one Lync.  Unless there is a way to integrate Office365 Lync Tenants as I've read that AADSync can work with one domain and two tenants by using two Sync servers.

In the end the requirement of the migration is that users should have one Outlook profile and keeping same SMTP email-address if the tenants should be merged.  

Looking for best list of pros/cons for merging and not merging along with easiest merge method. 

Thank you

Answer 1

Hi Apourwafa,

I have read the thread and understood you’d like to get a list of pros and cons for merging or not merging these two Office 365 tenants. And I’m going to briefly introduce these two different scenarios:

1. If you decide to keep two Office 365 tenants, you can use two sync servers to sync users to different tenants like you mentioned. However, please be aware that you have to use different custom domains in different Office 365 tenants as it’s not feasible to verify the same domain in two tenants.
2. Firstly, it’s not feasible to merge two tenants in Office 365. While if you mean to use just one Office 365 tenant, two companies can use the same domain in this case. As I know, you can filter OUs from the On-premises to better manage the company while it’s not feasible to do this in Office 365. Meanwhile, billings and administration of different companies cannot be separated. However, we can still achieve some goals in this situation. For example, if you want to filter emails sent to a specific company, you can set up dynamic distribution groups(DDGs) to do the trick.

Let me know if anything is unclear.

Regards,

Sam

Answer 2

Hi Apourwafa,

Do you need further help?

Thanks,

Sam

Answer 3

Hi Sam,

Thank you for your answer,

My Client has decided to keep and use both tenants in Office 365. We have already setup AADsync to sync users to different tenants, and it works perfect!, but as i said, the challenge is how can we configure O365 to use one SMTP address for the users on both Tenant's?! cuz the requirement of the migration is that users should have one Outlook profile and keeping same SMTP email-address.

Best regards..

Arash

Answer 4

Hi Arash,

Thanks for your updates.

I understand your requirement is to keep the same SMTP address in two different Office 365 tenants.

However, like I mentioned above, it’s not workable to verify the same domain in two Office 365 tenants at the same time. And there is also no workaround in this situation based on my knowledge. Thanks for your time and understanding.

Regards,

Sam

Answer 5

Hi,

Not sure if this is still an issue, but we've a similar thing here. We merged with another company, but we've currently kept our own identity, and we're on a different Exchange/Office 365 hybrid tenancy. For emails coming to us, CompanyA.com, but are for users in CompanyB.com, we've setup a contact within the exchange/office 365 global address list with a @CompanyA.com email, that has an external address of @companyB.com. That automatically sends the email on to the correct user account.

Hope this makes sense,

Cheers,

Jon