I recently discovered I was not receiving e-mail alerts from my NVX with 4.2.21. It was set to internal, and a test message appeared to be successfully sent, just never received. When I switched back to the gmail setting I thought it had been set for, the test message started coming through. I have not had any events that would have triggered an e-mail.
Remember - the NAS is not a backup plan.
Backup = Good, No Backup = Bad