r/exchangeserver • u/Spike__777 • 5d ago

Change hybrid routing address

Hi All,

Does anyone know how we update the routing address in Exchange Hybrid?

We have added a new onmicrosoft address to Office 365 as part of a rebrand and we now want to use this as our routing address but I can't get it to work.

I have tried running the HCW again but doesn't help.

If I do set the new address as the routing address for a user the new address never syncs as alias via cloud sync to Office 365.

Thanks

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3

u/jjgage 5d ago

PowerShell

3

u/ZC_NAV 5d ago

Why, the old addresses will stay. Safe you the work

1

u/Spike__777 5d ago

Company rebrand and they want to remove references to old name which can still be seen. Small thing but fussy marketing team.

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u/REngimann 4d ago

please explain what you mean by "routing address" - are you trying to get e-mail for your domain to route to the MS onmicrosoft server rather than your on-premise server? If so, you have to change the MX records for your domain to point to the MS cloud servers first (lower MX number) and, if you want a backup, to your on-premise servers second (higher MX number). If you have the hybrid environment set up properly, the MS servers will process the e-mail first and send any on-premise/active directory mailboxes to the on-premise server(s) if the user does not have an address in the cloud. If you don't change the MX servers, mail will route to your on-premise server first, then send anything it can't find in your on-premise/active directory to the cloud servers. Remember, user addresses/mailboxes do not automatically change to cloud addresses - you have to migrate your on-premise users to the cloud if you want cloud-based mailboxes.

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u/Spike__777 4d ago

This is purely the routing address between on prem exchange server and cloud used for hybrid.

We are trying to change it from one onmicrosoft.com address to a new one due to a rebrand.

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u/ablege 3d ago

The actual routing happens on the send connector of your hybrid server. The actual setup may be one of two methods. By default, the HCW wizard creates a send connector to O365 that is scopes to your xxxxxxx.mail.onmicrosoft.com domain which routes to your O365 EXO endpoint. You can add your new routing domain to that send connector scope. Alternatively, someone may have marked domains as non-authoritative in your hybrid server which causes Exchange to forward any messages it can't deliver to an on-prem mailbox to O365.

Start by looking at your Send Connectors since that the HCW default.

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u/7amitsingh7 2d ago

The Hybrid routing address is usually controlled through the targetAddress attribute. Adding a new onmicrosoft.com domain alone won’t change it. Check the user’s targetAddress and make sure Entra Connect/Cloud Sync is syncing the correct attribute. Also verify that the new domain is properly configured in Microsoft 365. This is especially important when managing an Exchange Hybrid migration to Microsoft 365.