OWA Doesn't Redirect in Hybrid Exchange

Occasional Contributor

I am working on a new Hybrid Exchange Deployment and cannot get the On Premise URL for OWA to display the redirect link for my ExchangeOnline mailbox.  Note that I am still testing and am using the Teams Exploratory licensing.


When my O365 test mailbox user uses the link to our On Premise OWA, the page displays "Something went wrong, we could not find a mailbox for this recipient. Either they don't have a mailbox, or don't have a license assigned."  The error references our on premise server.


The test mailbox is accessable from the URL configured in the organization relationship as the TargetOWAURL.  Mail is correctly flowing to and from the mailbox, and free/busy information appears correct to on premise users.  I ran the HCW without error.  I don't believe that we have a CNAME record configured for the redirect, but I would have expected to receive a redirect page, rather than an error.


What can I check to find out why this doesn't work?


Thanks in advance for any assistance!


Lisa J

5 Replies



Hi, when in hybrid, this is the expected behaviour.  You have some mailboxes still on premises, and some in the cloud.  Therefore, cloud mailboxes will access webmail via https://outlook.office365.com and on-premises will continue with the URL which will be set from your OWA virtual directory in Exchange and should be on your public SSL cert.


You won't be able to get that URL to point to different locations for on-prem and cloud mailboxes.

I took this one step further and setup a CNAME record per the instructions at https://docs.microsoft.com/en-us/exchange/hybrid-deployment/simplify-owa-url and that was the step that I was missing.  In the end, I was just confused by the message and stopped the setup before it was finished.  Now, the user gets a link to their O365 login.





Well I have learned something new there actually.  Never realized that you could do this.  Thank you for sharing your resolution! :smile:

I have also found that browser caching can interfere here. I needed to clear the browser cache for users whose mailboxes have moved. After that they got the correct redirect webpage.



Re: the cname solution - make sure to heed the note about how you have to only go to the cname FQDN using HTTP. If you try HTTPS, you get the scary warning about certificate name mismatch, which surely will ruin the user experience. Best to create a link or bookmark for users to click if using the cname solution, so they don't type or end up at HTTPS by accident.