Forum Discussion
Delayed delivery for Dynamic Distribution Groups
Hi all,
We have some problems with the mail-delivery for Dynamic distribution groups. We come from an on-premise Exchange 2013 environment. We created some Dynamic groups, based on the AD-organizational unit an account resides. This worked well.
When we migrated to Exchange 365, we created mail-contacts in E365, to enable the use of the (on-premise) Dynamic groups.
This all works fine, the only thing we see is that the delivery of some messages is delayed. Some users receive the messages within seconds of sending it; other users receive the message 60+ minutes after sending.
I think the problem could be with some sort of throttling the mailflow on-premise <>Exchange 365, but I can't find something. Does anyone have the same?
Recreating the groups in Exchange 365 is not an option for now, because the Dynamic groups are using ou's for filtering members...
Kind regards,
Arjan
13 Replies
- Last week we 'moved' the dynamic groups from Exchange on-premise to Exchange 365. After this action, sending with this groups seems to be without delay. Problem solved.
Thanks everyone for the suggestions!- Great to hear that and thank's for the Feedback!
Hi ArjanBroekhuizen,
The Problem is, that the Expansion (getting the Group Members) happens at the Time of the Delivery on your OnPrem Exchange Server and then sent to the Recipients back in Exchange Online.
Don't think it's related due to Throttling of old Exchange Servers yet.
https://techcommunity.microsoft.com/t5/exchange-team-blog/throttling-and-blocking-email-from-persistently-vulnerable/ba-p/3762078I've seen Messages through an OnPrem Connector could be handling about 10-20'000 Mails per Hour. So it depends on your Traffic that goes through the Connector.
To improve the Situation i see only the Option to move dynamic Distribution Group to Exchange Online (so the Expansion / reslove of the Recipients) happens directly in Exchange Online.
To get rid of OU Based filtering you need to add other Filter Criterias like Company, UserPrincipalName or EmailAddresses or any other Filterable Property.Filterable properties for the RecipientFilter
https://learn.microsoft.com/en-us/powershell/exchange/recipientfilter-properties?view=exchange-ps
Hope that helps
Regards
Andres Bohren
Hello Andres Bohren,
Thanks. Trottling of old Exchange Servers isn't related, because we have an up-to-date Exchange 2019 server.
I don't think the number of messages p/hour is the problem, our on-premise server isn't that busy. That's why I don't understand some messages are delayed...
Move the Dynamic Distribution Groups to Azure crossed my mind also, but that isn't an option at this moment. Because of the OU based filtering. The properties to filter are in serveral ou's where the groups are based on. In Azure this will result in a wrong groupmembersship.
Knowing that we have to move the groups to Azure in the future, we will work out scenarios to deploy.
For now I hope someone has a suggestion for the problem off the delayed messages.>Trottling of old Exchange Servers isn't related, because we have an up-to-date Exchange 2019 server.
You mentioned Exchange 2013 in your first post. That's why i was pointing in that direction.
Anyway only Exchange 2007 should be throttled at this point.
>I don't think the number of messages p/hour is the problem, our on-premise server isn't that busy
It's not what's your Server is capable of delivering. It's what's microsoft is willing to receive.
To get a Number. How big are the dynamic Distribution Groups. How many Members are we're talking about?
>Knowing that we have to move the groups to Azure in the future, we will work out scenarios to deploy.
That's the way forward anyway.
Maybe you have set an Expansion Server that don't exist anymore. Check this:
Get-DynamicDistributionGroup | ft name, ExpansionServer
Regards
Andres Bohren
Hi ArjanBroekhuizen,
As per your description, all the users from the DDG receive the messages, but some of them quite delayed. Probably it's not related to this, but I would suggest to have a look to this article and confirm that the DDG is configured correctly for that hybrid environment:
Dynamic distribution group members don't receive emails - Exchange | Microsoft Learn
- Hello FcoManigrasso,
Thanks for your reply. I have read the article. We don't have this issue; all accounts are member of the DDG and they all receive the mail. Only not all within a few minutes. Sometimes up to an hour.Hi ArjanBroekhuizen,
Thanks for confirming.
In that case, had you the chance the check a message header of a delayed message? There we should be able to see if there's any loop or where the message was stuck. It could also be useful to compare it with one delivered in time.
On the other hand, in O365 you have the queue report. Maybe there's something that gives you a light on this:
Exchange Online Admin Center - Reports - Mail Flow
