How to cache ALL emails in Outlook in Session Host.

Copper Contributor



Recently I deployed WVD for a client and costumers are calling and telling me they only see emails since 1months back.


I did a quick google search and found that, I can change the sync settings in regedit.

Computer\HKEY_CURRENT_USER\Software\Policies\Microsoft\office\16.0\outlook\cached mode

I changed all values from 1 to 12. (all this is made on session host)


But users still cant sync more than 1months of emails.


I tired logging in with my own O365 account in the admin profile and it sync ALL mails.


How do update the settings on my users?

8 Replies
You should also post your question to outlook forum, You may get better response from there.
Even though it's regarding RDS/WVD? i want the setting to apply to all my users
Even though it's regarding RDS/WVD? i want the setting to apply to all my users
best response confirmed by SamirAbdouCloud (Copper Contributor)



HKEY_CURRENT_USER hive is only for your current profile, so it wont change it for everyone.

Outlook profile settings are per user. So you will have a better luck with a GPO with the corresponding Office suite ADMX set.

Are you sure the group policy approach works? See The group policy isn't working for me either.
I was struggling with this as well. The default Azure Image with M365 Apps configures the recommended registry settings as mentioned in:

I have tried setting the syncwindowsetting to 0 with GPO and then Apply my own GPO settings for caching in Outlook for 1 year. But that still didn't work. It just changed the cache to ALL (so if that is what you are looking for ;), but not recommended).
Changing my GPO for the registry value to "DELETE" worked. This deleted the registry value and with this my Office GPO kicked in and Outlook cache for new and existing profiles is not set to 1 year.
which reg keys did you change? I am having this issue as well
There are two ways to solve this.

For existing user
Change registry value at
HKEY_CURRENT_USER\Software\Policies\Microsoft\office\16.0\outlook\cached mode\
Find value syncwindowsetting
Change it to the value you want by referring to this document (You need to change based on decimal to make it work, and the user must have administrator permission to be able to change)

For new user, make sure you have following registry value created before you setup a new user with new outlook profile.
Create key outlook
and underneath it
Create key cached mode
And create DWORD value (Decimal)
The value input just references the document I mentioned above

Hopefully this helps.