That view is showing all e-mails with issues. Deferred e-mails will be retried. Bounced e-mails indicate undeliverable and the e-mail for that user is marked as 'bounce'. For example if a user was added to Samanage before the actual e-mail setup was completed. In that case you can send an e-mail to email@example.com to have the bounce marking cleared.
To confirm emails are sent/delivered or even opened.