Different Retention Policies for Active/Inactive Mailboxes

Cloud Environment:

Azure GOV tenant, GCC-High.

Users are licensed with:

MS365 E3 - GCCHIGH

MS Defender for Office365 (Plan 1) - GCCHIGH

Windows 10/11 Enterprise E5 - GCCHIGH

Hybrid Identity:

Users are synced from AD DS to Entra ID, via Entra Connect. Thus, we set various identity attributes, like "Department" using the AD DS attribute editor. Confirmed the "Department" attribute is syncing correctly to Entra ID.

Purview Adaptive scopes:

Active Mailboxes (user), oPATH query: (IsInactiveMailbox -eq "False")

Inactive Project Staff (user), oPATH query: (IsInactiveMailbox -eq "True") -and (Department -eq "project staff")

Inactive Contract Staff (user), oPATH query: (IsInactiveMailbox -eq "True") -and (Department -eq "contract staff")

Purview Data Lifecycle Management, Retention policies:

Default Data Retention (Exchange mailboxes) - Adaptive scope "Active Mailboxes", Retention: Keep content for 7 years, then do nothing.

Inactive Project Staff (Exchange mailboxes) - Adaptive scope "Inactive Project Staff", Retention: keep items for 3 years, then delete items automatically.

Inactive Contract Staff (Exchange mailboxes) - Adaptive scope "Inactive Contract Staff", Retention: keep items for 1 years, then delete items automatically.

Desired Outcome:

• All active staff, regardless of Department attribute have the "Default Data Retention" policy applied to mailbox, so when their account is deleted in AD DS, (soft deleted in Entra ID after Entra Connect sync), their mailbox goes to inactive state.
• Then, when the mailbox is inactive, the "Inactive" retention policy is automatically applied depending on what their Department attribute was, before their Entra ID identity got soft deleted by Entra Connect sync.

Problem/Questions:

We tried this for 1 user account, and although the Default Data Retention policy was applied before the user was soft deleted, the Inactive Project Staff policy was never applied (waited 4 days).

• This test user didn't have any licenses assigned to them when we tried this, unfortunately. Could this be the reason why the Inactive Project Staff policy was never applied? When they were soft deleted, their mailbox was visible in Purview "Inactive mailboxes".
• Will adaptive scope retention policies still be applied to inactive mailboxes, if that adaptive scope relies on an Entra ID attribute, like "Department"? I assume this Entra ID attribute is somehow stored in the now, inactive mailbox.