Outlook .ost concurrent sessions, keeping it small, preventing dfs replication

[EricNichols]

We are 100% non persistent VDI with UEM & Win10. Since some of our staff are in more than one pool concurrently, redirecting the ost to a network location results in the second in vdi to have file locking issues on the .ost. So that option is out. Apparently, the ost and exchange server only allow one .ost file with the same GUID to maintain sync. If you try to sync .ost between two pools, you'll get a message that you are using an older copy of the .ost file. You can then proceed to send and read mail but you won't receive any new mail.

With this setup described below, we only allow one vm per user per pool.

We used the UEM built in outlook template (direct flex disabled) with a slight modification pasted below. We added the capture of <localappdata>\microsoft\outlook but excluded the ost.

With another config (pasted at the bottom) named OutlookOST, we collect the ost (direct flex enabled). This allows us to put it into a separate .zip so that it and it's backup can be excluded from DFS replication and allows us to target it for deletion and future maintenance. The direct flex for the ost is based on outlook.exe and lync.exe. Using direct flex for ost allows us to have a faster login but slower lync or outlook launch. If you dont add the lync.exe as a direct flex, if skype launches before outlook (autorun), it will create a new empty .ost which will suck up bandwidth as it rebuilds each login. With multiple sessions\pools, this config gives you a last one out wins scenario.

We also had to apply a GPO to the second pool (isolated by OU) to force Outlook into online mode so that it wouldn't conflict with the pristine .ost. Here are those settings:

HKEY_CURRENT_USER\Software\Policies\Microsoft\office\16.0\outlook\cached mode DWORD: enable Value: 0 HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\16.0\Outlook\OST DWORD: NoOST Value: 2

We found that UEM sometimes fails to capture the .ost. This was happening if the .ost was larger that 2GB. So we are using GPO to limit the cache to 3 months. Its looking like 3 months is averaging 500-800 MB. I wish there were more features to keep the .ost from growing beyond a certain size without breaking any outlook features. Right now if we impose the .ost size limit to 1gb, if someone exceeds that with 3 months of mail, outlook does not let them delete mail, receive new mail or move mail to folders. If this causes too many problems we might need to cache even less or go to online mode. Auto archive might be an option but even that does not let you archive based on .ost size.

Maybe someone else has come up with a solution for limiting the .ost size without breaking outlook features. Is there a UEM timeout to allow larger files time to .zip up?

Outlook without direct flex, export at logoff

[IncludeFolderTrees]

<LocalAppData>\Microsoft\Outlook

[ExcludeFiles]

<LocalAppData>\Microsoft\Outlook\*.ost

[IncludeRegistryTrees]

HKCU\Software\Microsoft\Office\16.0\MAPI

HKCU\Software\Microsoft\Office\16.0\Outlook

HKCU\Software\Microsoft\Office\Outlook

HKCU\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\Profiles

[IncludeIndividualRegistryValues]

HKCU\Software\Microsoft\Exchange\Client\Options\PickLogonProfile

[IncludeFolderTrees]

<AppData>\Microsoft\Outlook

<AppData>\Microsoft\Signatures

[IncludeFiles]

<LocalAppData>\Microsoft\Office\olkaddritem.officeUI

<LocalAppData>\Microsoft\Office\olkapptitem.officeUI

<LocalAppData>\Microsoft\Office\olkdlstitem.officeUI

<LocalAppData>\Microsoft\Office\olkexplorer.officeUI

<LocalAppData>\Microsoft\Office\olklogitem.officeUI

<LocalAppData>\Microsoft\Office\olkmailitem.officeUI

<LocalAppData>\Microsoft\Office\olkmailread.officeUI

<LocalAppData>\Microsoft\Office\olkmmsedit.officeUI

<LocalAppData>\Microsoft\Office\olkmmsread.officeUI

<LocalAppData>\Microsoft\Office\olkmreqread.officeUI

<LocalAppData>\Microsoft\Office\olkmreqsend.officeUI

<LocalAppData>\Microsoft\Office\olkpostitem.officeUI

<LocalAppData>\Microsoft\Office\olkpostread.officeUI

<LocalAppData>\Microsoft\Office\olkreportitem.officeUI

<LocalAppData>\Microsoft\Office\olkresenditem.officeUI

<LocalAppData>\Microsoft\Office\olkrespcounter.officeUI

<LocalAppData>\Microsoft\Office\olkresponseread.officeUI

<LocalAppData>\Microsoft\Office\olkresponsesend.officeUI

<LocalAppData>\Microsoft\Office\olkrssitem.officeUI

<LocalAppData>\Microsoft\Office\olkshareitem.officeUI

<LocalAppData>\Microsoft\Office\olkshareread.officeUI

<LocalAppData>\Microsoft\Office\olksmsedit.officeUI

<LocalAppData>\Microsoft\Office\olksmsread.officeUI

<LocalAppData>\Microsoft\Office\olktaskitem.officeUI

OutlookOST with direct flex on outlook.exe and lync.exe, export at logoff with a condition to not download to the second pool.

[IncludeFiles]

<LocalAppData>\Microsoft\Outlook\*.ost