ABAC is implemented in our app to restrict Read access to users that are not part of a HubName. The Hub name is defined in a special .HubName property in the case type.
ABAC is also using the OOTB “isBatchRequestor” when rule. (screenshot of the setup below)
For browser requester type alone have your logic getting defined in ABAC for checking Hub condition. For other requester types you can allow the system to access the cases without any validation.
Email listener will come under App Requester type. I am not sure any OOTB when rule avail to check App Requester type similar to batchrequester. If when rule avail to validate App Requester then by using that you can remove the security restriction for that requester type also.
I’ve managed to solve the issue by creating a custom function similar to the isBatchRequestor. Followed the same components & the exact same code with just a small change in the end: