Exchange 2013 not forwarding email to clients

Hello All,

I apologize my ignorance on Exchange beforehand, it is my first time implementing one up.

I have recently implemented an Exchange 2013 box in my organization.

We were currently running a Hybrid configuration with an on Premises Exchange 2007 server and Office 365. We will soon be migrating our MX ( to office 365.

This new Exchange 2013 box was implemented in order to host a couple of mailboxes and groups that will be used on our LOB applications. Another MX and namespace ( has been configured and tested to be handled by this server. This Exchange 2013 is now in coexistence with my on premises Exchange 2007. A new SMTP address has been added to my users with this new namespace.

When I send an email to this new domain namespace (from internal or external account) to any of my users, It does not arrive to the email client for some reason and I am not getting any email delivery notification back that can help me out troubleshooting the situation. I have been looking for logs everywhere and I have not found anything that can give me a hint of what could be happening.

I am most probably missing some extra configuration.

Any help on this is greatly appreciated!
Who is Participating?
Vasil Michev (MVP)Connect With a Mentor Commented:
Again, message trace is your friend. One of the common issues with hybrid connectors is enforced TLS with invalid certificate, in which case the mail will be dropped. You can simply disable TLS (use Opportunistic TLS) in the connector settings and test like this.
Simon Butler (Sembee)ConsultantCommented:
If the SMTP domain has been added to the Accepted domains list and there is a match email address on an object, then email should be delivered.

Run a telnet test in to the server, so you can see it is has been delivered, then use Message Tracking to see what Exchange has done with the message.

Vasil Michev (MVP)Commented:
Where are those mailboxes hosted? If the MX is pointing to on-prem and the mailboxes are hosted in the cloud, most likely the issue is with the connector. Have you rerun the hybrid wizard after you added the domain?
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LuiLui77Author Commented:
Thanks guys for your comments!

Vasilcho I have not rerun the hybrid wizard after I added the new domain/Exchange 2013, I thought it was not necessary. We will soon decomissioned our Exchange 2007 when we move our MX to Office 365 and I dont want our Exchange 2013 to have a connection with Office 365 whatsoever.
Is there anyway to configure the connector, without having to run hybrid setup again?

Please correct me if I am wrong in any of my statements.

Vasil Michev (MVP)Commented:
Rerun it, it will modify the connectors, organizational relationship and the rest.

Any results from the message trace?
LuiLui77Author Commented:
It seems that the only way to track a message is from the delivery report, and I am not getting anything from it, not even the option to choose a mailbox, I believe is because all mailboxes are in the cloud. (correct me if i am wrong)

Is there any log files that I can check?
Vasil Michev (MVP)Commented:
Use message trace, not delivery reports. You can run the trace from O365 as well, in both cases it should be in EAC -> Mail flow -> Message trace
LuiLui77Author Commented:
Hi Vasilcho, In the EAC --> Mail Flow, the only options that I have on top are:
Rules, Delivery Reports, Accepted Domains, Email address policies, receive connectors, send connectors

I don't see message trace anywhere.
Vasil Michev (MVP)Commented:
You need to be a member of any of these groups:

Organization Management
Compliance Management
Help Desk

You can also run it with the Get-MessageTrace cmdlet.
LuiLui77Author Commented:
Hey Vasilcho, Emails are being routed, as a matter of fact they were since the beginning.

I confirmed this by creating a new user and then creating a mailbox for the user. I noticed that when creating the mailbox, a couple of SMTP emails were created, one with my actual namespace ( and another one with the new namespace configured on the new Exchange 2013 (

I sent a couple of emails to this new user using the exchange 2013 namespace ( from my external and internal email. I logged into the OWA as this new user and saw the emails were received.

What i am doing differently now is that I created a new user and mailbox. What I did before was that I created a Distribution group on my AD, were the members were all users which mailboxes have been already migrated to Office 365, probably you can give me some idea to make this happen, well i will most probably create another post for this.

Now the issue is that i am unable to send emails from this new user. I am guessing is something wrong with the send connector on this new Exchange 2013 box.

Remember that besides this new Exchange 2013 box, I have a hybrid setup between an on-premises Exchange 2007 and Office 365, almost all of the mailbox have been migrated.

LuiLui77Author Commented:
Hi Vasilcho, Thanks for helping out troubleshooting. I created a new send connector configuring my new Exchsnge 2013 box as the source and VOiLA, we are sending emails.

In order to confirm that the Exchnage server routing the email was the one specified, I opened up the properties of the email and checked on the header and there it was FROM: my Exchange 2013 box.

Thank you again.
LuiLui77Author Commented:
Vasilcho, very responsive, Thanks!
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