Exchange 2016 CU18

Question

Since we upgraded to Exchange 2016 CU18 everyone in the office is having sync issues with every single email having issues. I have created new profiles and new ost files but still getting the issue. The only way to fix it is to disable cached exchange mode, I dont really want to do that for 100 users. They sync issue would pop up about 30 seconds after the email was received in the mailbox. Everything I research seems to point at the OST but there is no way that it can be that as ive rebuilt it several times and its affecting multiple users.

Exchange 2016 and outlook 2016, same problem happens when I use outlook 365

Answer 1

To fix the message size of ActiveSync device, locate to %ExchangeInstallFolder%\Program Files\Microsoft\Exchange Server\V15\ClientAccess\Sync, open Web.config file and search "MaxDocumentDataSize", then increase it to higher value, also search "MaxRequestLength" and increase it too.

Quota from Web.config file:

<add key="MaxDocumentDataSize" value="10240000"></add>
.......
<httpRuntime maxRequestLength="10240" />

For Exchange 2016 server, it's fine if you uninstall .Net 4.7.1 and re-install 4.6.2 correctly.

I hope answer the question if issue resolve please accept answer

Answer 2

Hi @Marlow Schlebusch ,

I've tried to search a lot but currently haven't seen similar reports about sync issues in Outlook with CU18.

Given this, would you please provide more details about the sync issue so that we can help do further research on this?

They sync issue would pop up about 30 seconds after the email was received in the mailbox.

So by sync issue, do you actually mean the Outlook users encounter a 30 seconds around delay in receiving messages when they are in cached mode, but emails can be received timely in Exchange Online mode or using OWA?
If this is the case, will the users be able to see the message in Outlook after pressing the Send/Receive All Folders(F9) button?

Besides, please have a check to see if there's any relevant logs in Event Viewer.

---

If an Answer 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.

Answer 3

So, this is the sequence of events

At 09:39:18 I send myself an email then
at 09:40:01 it pops up in my Conflicts folder and Sync issues folder.

The original email in the inbox then has a notification at the top that says "This is the most recent version, but you have made changes to another copy. CLick here to see the other versions."

There are no other version as I've not done anything yet.

This is the case for any email that we receive and it only happened since the CU18 update, we upgraded from CU13

Its worth pointing out that we use vipre email security that checks incoming email.

Answer 4

Hi all,

Exchange 2016 CU19 is out. May I know whether it resolved the issue found in CU18?

Thank you.