Distribution and email enabled security groups are not delivering to members in hybrid exchange running 2010 on-premise

Question

We are running in Hybrid mode with intention of eventually migrating everyone to the cloud. We only have a few test accounts on the cloud. We won't be doing any real mailbox migrations until we can fix this current issue.

Direct mail delivery to users from outside works fine. If I send a mail from my gmail account it hits office 365 and then routes to our on-premise  exchange server. Mail will also deliver to external contacts and our on-premise public folders (setup as contacts with the targetAdddress attribute modified) that are members of the group. I've switch our MX record back to deliver mail directly to on on-premise server for now but I can still reproduce the problem by trying to send to a distribution list with on-premise members from one of our cloud test accounts.

I went to the mail trace and looked at a few of the messages. The one test distribution list that delivered successfully has two different looking message trace entries, One for the successful delivery and the one that disappeared. The status of the successful delivery is says "Delivered" and the status of the message that disappeared is "Expanded"

I also checked the logs on the Exchange 2010 server for any of the missing messages. I could find the ones that were delivered successfully but none that showed up as "Expanded" on the Office 365 admin center as "Expanded". Those vanish into thin air. 

Any help is appreciated.

Answer 1

Hi Revilo,

This issue was posted to the Service Health Dashboard (SHD) as incident EX100699 starting at Monday, May 1, 2017 12:00:00 AM (UTC). The user experience of this incident is: Admins are unable to use message tracing to determine if messages are being properly delivered. Tenant administrators can view current information and updates on SHD at the link here:

https://portal.office.com/admin/default.aspx#@/ServiceStatus/ServiceStatusHistory.aspx

For affected customers to easily identify the information here, this thread will be closed.

​We will update to the primary thread below once the issue is resolved or you can obtain the most recent information from SHD.

https://answers.microsoft.com/en-us/msoffice/forum/msoffice_o365admin-mso_exchon/message-trace/505e9315-bfc1-445c-86b8-82060cc11e6d?tm=1494346764115

If you are experiencing a similar issue and do not see an SHD post, please let us know by sharing your tenant information via Private Message: https://answers.microsoft.com/en-us/privatemessages/list.

Thanks,

Brook