Purview DLP Behaviours in Outlook Desktop

Would love to know how you got the policy tip to display in New Outlook desktop. Have tried but cannot get it to show, even with -DLPWaitOnSendEnabled on the tenant. The policy tool displays as expected in Outlook web when criteria is met, but does not show in New Outlook desktop. All we get is the notification before send that the org evaluates emails for sensitive info.

We use SIT as part of the criteria. From your screenshot, it implies you're using labeled content for criteria, which may be the deciding factor. Could you share a screenshot of your purview policy that utilizes policy tips, if possible?

Hi,

These are known issues 

Override without justification (Send Anyway without selecting a reason)

This is actually expected behavior unless you explicitly enforce justification via configuration. By default, Outlook presents the oversharing dialog but does not gate the send action on the user completing a justification. To enforce this you need to configure the following.

GPO:

Classic Outlook
Specify wait time to evaluate sensitive content at Software\Policies\Microsoft\office\16.0\Outlook\options\Mail
Registry:
Key: DLPWaitOnSendTimeout (DWORD)

New Outlook
Registry via Exchange Online Mailbox parameter in Powershell (there is no Policy option)

Connect-ExchangeOnline 
#for the entire organization 
Set-OrganizationConfig -DLPWaitOnSendEnabled $true -DLPWaitOnSendTimeout 25 
#for specific mailbox only 
Set-Mailbox -Identity "email address removed for privacy reasons" -DLPWaitOnSendEnabled $true -DLPWaitOnSendTimeout 25 
#verify the setting 
Get-OrganizationConfig | Select-Object DLPWaitOnSendEnabled, DLPWaitOnSendTimeout

On the timeout value the following:

0 = user immediately sees "Send Anyway" — effectively no enforcement
1–9998 = Outlook waits that many seconds for evaluation to complete before allowing override (25–60 seconds is a practical range)
9999 (default) = mail will not be sent until DLP evaluation fully completes — strictest option

Inconsistent policy tip display

The two build you mentioned (Click-to-run vs MSO) are different build types and can render the oversharing dialog differently. This is a known inconsistency in classic outlook across mixed build environments.

On a broader note

Classic Outlook is on a deprecation path, so rendering inconsistencies are unlikely to receive dedicated fixes. New Outlook has a more consistent and actively developed experience; migration is worth considering as a longer-term solution.