Mail flow between on-premises Exchange 2013 and Office 365

[adamf]

We have an on-premises Exchange 2013 server and Office 365 in a hybrid configuration. We want all mail to flow through the on-premises server for compliance reasons and for the most part have that working.

 

We are struggling with mail from the internet reaching Office 365. It is delivered to our on-premises Exchange 2013 server but does not get delivered to the test mailbox in Office 365. Instead it gets stuck in the Submission queue on the Exchange 2013 server because a local loop has been detected.

 

I've gone through the hybrid configuration wizard many times and cannot figure out why this isn't working. All other mail flow to and from Office 365 is working as expected.

 

 

Does anybody have this working and can point me in the right direction?

[EduTech]

We have an on-premises Exchange 2013 server and Office 365 in a hybrid configuration. We want all mail to flow through the on-premises server for compliance reasons and for the most part have that working.

 

We are struggling with mail from the internet reaching Office 365. It is delivered to our on-premises Exchange 2013 server but does not get delivered to the test mailbox in Office 365. Instead it gets stuck in the Submission queue on the Exchange 2013 server because a local loop has been detected.

 

I've gone through the hybrid configuration wizard many times and cannot figure out why this isn't working. All other mail flow to and from Office 365 is working as expected.

 

 

Does anybody have this working and can point me in the right direction?

 

Hi,

 

I am assuming that the Exchange 2013 Hybrid Configuration Wizard is completing successfully without any problems

 

- Does an email sent from an Exchange 2013 On-Premise Mailbox send to an Exchange 2013 Online Mailbox

- Does an email sent from an Exchange 2013 Online Mailbox Send to an Exchange 2013 On-Premise Mailbox

 

Please can you check the following:

 

- Login to Exchange Online > Admin Centre > Mail-Flow >Connectors and ensure that the inbound & outbound connectors have been setup correctly i.e. contain the correct IP Address & Certificate Name.

 

- Ensure Ports 25 and 997 are open inbound and outbound between Hybrid Server & O365 Data centre IP Address. To get a list of the Data Centre IP Address run the following Powershell Command.

 

Get-HybridMailflowDatacenterIPs | select -expand DataCenterIPs

 

- Ensure that your receive connectors do not specify the IP Address of your Exchange Hybrid Server

 

Let me know how you get on after checking that,

 

Regards,

James.

Edited April 9, 2013 by EduTech

[adamf]

Mail is flowing from on-premises to Office 365, Office 365 to on-premises and Office 365 to Internet (via on-premises).

 

Connector wise:

 

Inbound from 7f7d446a-1a5c-4614-95ae-88f602926768

 

Has the correct certificate assigned to it, domains is set to * but it has nothing under IPs

 

Outbound to 7f7d446a-1a5c-4614-95ae-88f602926768

 

Sending outbound mail to Smart Host which is the public IP of the Exchange 2013 server.

 

Port 25 is open but only to some of the IPs from the powershell command, 997 isn't open at all.

 

Where am I looking for the receive connectors on Office 365?

[EduTech]

Inbound from 7f7d446a-1a5c-4614-95ae-88f602926768

 

Has the correct certificate assigned to it, domains is set to * but it has nothing under IPs

 

Your Inbound Connector should have an IP Address of your Exchange Hybrid Server set as the Sender IP Address.

 

Outbound to 7f7d446a-1a5c-4614-95ae-88f602926768

 

Sending outbound mail to Smart Host which is the public IP of the Exchange 2013 server.

 

Your Outbound Connector should be set to Smart Host Indeed, which should then specify the Exchange 2013 FQDN, Your domains should be restricted in the scope and connector security should be TLS and matches the SSL Certificate FQDN.

 

Port 25 is open but only to some of the IPs from the powershell command, 997 isn't open at all.

 

Hybrid Deployments require that port 25 and 997 is open for between the hybrid server and the datacentre IPs specified when you run the command mentioned above. If this is not the case then it won't work as it needs to communicate via 25 and 997 (TLS)

 

Where am I looking for the receive connectors on Office 365?

 

Sorry, I am assuming here that you are using the new version of office 365 is this the case and if so I mentioned this above login to your tenancy and then go to Admin > Exchange Online > Mail Flow > Connectors which then shows both your Inbound and Outbound Connectors... or are you using Exchange 2010 Online?

 

Regards

 

James.

Edited April 9, 2013 by EduTech

[adamf]

I've checked all of that and made a couple of changes. I'll get port 997 opened in the firewall tomorrow and test it again.

 

Cheers

 

Adam.

[EduTech]

I've checked all of that and made a couple of changes. I'll get port 997 opened in the firewall tomorrow and test it again.

 

Cheers

 

Adam.

 

No problem, If you need any further assistance let me know I am available tomorrow morning if you want a hand to go through a few things.

 

Be sure to check out the Exchange 2013 Hybrid Deployment Assistant if you want to go through the steps: Exchange 2013 Deployment Assistant

 

Regards,

James.