In the event that the alert is not acknowledged and it proceeds to the next step in the escalation process will both alerts be sent or just the one set to fire after the initial notification? i.e. email1 is sent but not ack'd after 30 min so email2 is sent; if this occurs will both email1 and email2 be sent or will only email2 be sent?
If the trigger condition is still true, and the alert has not been acknowledged after 30min (as stated in your example) then one email will be sent to recipient 2. No additional emails are sent to email recipient 1 after the first, initial email was sent when the trigger condition was originally met UNLESS the option to "Execute this Action repeatedly while the Alert is Triggered" every "x" minutes is also set.