Outlook cache mode and hybrid Exchange problem

Question

Hi all,&nbsp;We have done an hybrid migration from an Exchange 2010 to Exchange online, we migrated all mailbox to the cloud and everything worked fine.&nbsp;Last week, I have installed a new Exchange 2016 with hybrid licence and run the Hybrid configuration wizard, it worked. I can onw create mailbox from the local exchange directly to Office 365 which is great. For the moment the Exchange 2010 is shutdown, NOT decommissioned, it's temporary to be sure that this server is no more needed for anything else.&nbsp;But since last week, users have problem in Outlook. Outlook is in cached mode for last 6 months and from Outlook it's now impossible to get older mail. From a search or when I scroll the inbox, there is only cached mails. From the webmail, all mail are available. Otherwise Outlook is working great, users receive and send e-mail without any problems.&nbsp;Does anybody have an idea where the problem is?&nbsp;If you need more information I stay available.&nbsp;Thank you for you help.&nbsp;Regards

deleted · Answer

This is expected behavior nothing wrong with your setup. Everything is based on that cache setting. So if you want everything you have to up your cache or have no caching. What we do is tell users to use outlook on the web when looking for old messages.

julien schneider · Answer

Hi Christopher,&nbsp;Thank you for your answer, but I don't think that's how cache is working. We use cache for other customers and the behavior is that Outlook store recent mails (depends of the cache duration) in local so even without internet, mails are available and if the user want older mail then with a search he can retrieve what he want in Outlook.&nbsp;And in the fact, it was working last week, I think before the fresh install of the Exchange 2016.&nbsp;Do you have another idea ?&nbsp;Thank you&nbsp;&nbsp;

deleted · Answer

Yeah that’s how it used to work. Ever since moving To exchange online it no longer works that way. THey probabaly moved the same updates to exchange 2016 if your experiencing the same onprem they must have moved the same tech onprem in newer versions. It’s something to do with it only able to pull 500 records or something like. Been too long since I knew technically why it does it but I just know that’s how it works since moving to exchange online

julien schneider · Answer

Hello,&nbsp;Thank you for you answer, from my point of view and I think I'm not the only one, if what you said is right, it's a really bad choice from Microsoft. Do you have any official documentation that explain the cached mode with Exchange Online ?&nbsp;What I don't get is that on another account from another O365 tenant, the cached mode works well. I have 1 year of local e-mail and I can search on the server from Outlook without any problems.&nbsp;It seems really strange to me.&nbsp;Thanks

deleted · Answer

Now that I think about it, I'm betting because Online Archives have been turned on, the whole new "Sync shared mailboxes offline" is causing this issue possibly, and applying to your main folder as well. Worth a shot. Check out method 2 in this article.https://support.microsoft.com/EN-US/help/3140747Turn that off and see if it affects the primary mailbox as well.But even in this article: https://support.microsoft.com/en-us/help/2733062/only-a-subset-of-your-exchange-mailbox-items-are-synchronized-in-outlo&nbsp;that lead me to that it says if it's configured to anything other than all, your only going to see the offline items, your supposed to get a "Search items on server link thou". Which I know in the past I've had that issue where it doesn't show that either but right now it seems to be working normal again. I'll have to ask the support guys at work. But if you want to try that option above and see if it doesn't anything for you.

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Outlook cache mode and hybrid Exchange problem

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