01-23-2018 05:29 AM
01-23-2018 05:29 AM
Current setup is 2 forests with 2 exchange servers, 2 domains linked via trust. Both Exchange servers are completely separate.
We have been running AAD sync on one member server (in domain a )that syncs domain users from BOTH forests to our Office 365 Tenant.
Currently the on premise exchange servers each receive mail for their respective domain users, a.com and b.com.
I would like to migrate via minimal exchange hybrid each exchange forest to O365, it seems that I would then need to keep both servers on-premise to manage users etc.
Once each exchange is hybrid and mailboxes have been migrated for all users - how possible/easy at this point would it be to allow all users to use domain a.com email address ( and to have b.com as alias )
01-23-2018 10:32 AM
I'm not sure minimal Hybrid is supported with multi-forest scenarios, best contact support to confirm that. Once you get the mailboxes to O365, you should have no problems assigning aliases from either domain though, as they will be in the same organization.
01-24-2018 01:19 AM - edited 01-24-2018 01:19 AM
Hi thanks for mentioning that, hopefully I can get this confirmed.
setting an alias would only allow you to receive to that address? I would want all users to have the same email address for sending/receiving.
01-24-2018 04:19 AM - edited 01-24-2018 04:23 AMSolution
Yes, you can ;)
Minimal hybrid supports multi-forest Exchange hybrid deployments.
https://blogs.technet.microsoft.com/exchange/2016/06/24/hcw-improvement-the-minimal-hybrid-configura... --> have a look at the comments, Tim from Microsoft answered the question.
Alias: you can send email from an address which is the reply address of your mailbox. You can use address rewriting or similar features to accomplish this.
01-24-2018 05:45 AM
01-24-2018 05:55 AM
As you will keep your on-premises Exchange at least for recipient management, you can use it as an address rewrite gateway:
Exchange Online also supports Address Rewrite, which routes outgoing email through an on-premises gateway that modifies the addresses. This feature enables you to hide sub-domains, make email from a multi-domain organization appear as a single domain, or make partner-relayed email appear as if it were sent from inside your organization. Administrators configure custom email routing within the Exchange admin center (EAC).
05-21-2018 02:58 AM - edited 05-21-2018 02:59 AM
Unfortunately the address rewriting feature is not supported on Exchange online.
There exists a non-MS cloud service that implements the sender address rewriting function for Office 365/Exchange online.
by James Sillett on June 05, 2018
by Victor bassey on February 21, 2018