This browser is no longer supported.
Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(128, 8%, 22%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EA%3C/text%3E%3C/svg%3E)
We have begun migrating to Office 365 from Exchange and are currently in hybrid with some users migrated but most not. We have a routing situation that I am struggling with and hoping for assistance.
In Exchange on-prem we have a subdomain defined as an internal relay domain called bot.company.com. The reason for this is we have custom bot running on a server that we have to be able to send certain emails to for custom processing. In Exchange we have a send connector that routes emails addressed to anything ending in @Bot .company.com to a smart host, which is the server running the bot. This has been working fine.
We now need to be able to send to it from 365. I've added the domain to 365 as an internal relay domain and created a send connector that points directly to the bot server as a smart host. However, when I send to it the email goes to the on-prem Exchange server and not the bot server. The Exchange server then routes to the bot server, so it is working, but it does not appear to be using the send connector I created.
Can someone advise me on the correct way to set this up? Do I even need a send connector in 365 and, if so, how would I get it to send directly to the bot server instead of to Exchange first?
Thanks
Yes, you would need to create an outbound connector for that address space and it should take precedence over the "regular" hybrid connector you use for other mail to Exchange. Is the bot.company.com address space defined in the other connector?
You will want to make sure the regular hybrid connector is set like this and not for all accepted domains,.
I probably should have mentioned that we are using centralized transport. So all email goes through our Exchange servers on premises. The "regular" send connector is set for "Only when email messages are sent to these domains" with the only domain defined as * and the smart host is the Exchange servers.
Then we have a send connector for the bot address space also with "Only when email messages are sent to these domains" but with just the bot.company.com domain and smart host set to the bot server.
What's happening, though, is that all email, including the bot ones are getting routed to Exchange and then Exchange has a send connector for bot, which is sending the emails to the bot server. So the bot connector defined in O365 is not being used. Since Exchange will eventually be going away we'd really like to route these emails directly to the bot server.
Do I need to use the transport rule as described below by LucasLiu-MSFT? Would that resolve this?
The issue there however is that with Centralized Routing enabled, you are telling EOP to route all mail through your on-prem Exchange Servers. in other words, this is by design.
If you were to change HCW to use the standard routing, it would work as expected.
https://learn.microsoft.com/en-us/exchange/transport-routing
So you don't think it would work if I create the transport rule?
I'd try it, Why not? :)
But remember, it should work now the way you have it configured - the specific address space should take precedence.
But it maybe that the rule somehow bypasses the Centralized Routing logic, so I'd test it out.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(252.8, 22%, 34%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ELL%3C/text%3E%3C/svg%3E)
Hi anonymous user ,
Please try following steps to create a connector and transport rule.
----------
If the response is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.
Hi anonymous user ,
I noted that you are using centralized mail transport, I agree with what Andy said. If you enable the centralized mail transport, except for message sent to other recipients in the same Exchange Online organization, all messages sent from recipients in the Exchange Online organization are send through the on-premises organization, it’s by design.
So please try to create a transport rule and see if mail flow will change.
----------
If the response is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.
Hi anonymous user ，
I am writing here to confirm with you how thing going now? If the above suggestion helps, please click “Accept as answer” to mark helpful reply as an answer.Your action would be helpful to other users who encounter the same issue and read this thread.
Thanks for your understanding.
----------
If the response is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.