The request is from agents who would like to remain UNAVAILABLE after completing the email. Sometimes, they are preparing to go on BREAK or LUNCH or to end the day and want to finish that last email without being pushed another one. When they are pushed that next email, they would have to get out of ROUTING MODE and go into INBOX MODE and will have a missed interaction. Or, their Max Agent becomes AVAILABLE and is pushed a skill call and they can not reject the call.