We're using ZCS 6.

We've created a custom auth handler and it's working quite good, pretty straightforward.

However is it possible to have Zimbra verify the validity of a user's session every so often ... either every X requests to the backend or every X minutes etc.

To be clear I don't mean validate the Zimbra session itself, obviously this is already happening. We'd like to have the system verify our authentication system's token validity periodically.