Allow users to specify when the OOO auto-response is sent out

Allow users to specify the OOO behavior while setting it up to send the responder to a single recipient ONCE IN A SINGLE THREAD in 4 days. This may resolve the response delays as users will be notified immediately.

Attached is an example of how this would look:

Auto-responder will be sent once in 4 days on each thread from the unique sender.

If disabled, the auto-responder will be sent once regardless the email thread