The way to view emails is through the Reporting -> Email Log Report
You can use this to confirm the email was sent but you may also be be able to access it through the sent e-mails within the e-mail that it was sent from.
What we also suggest is to have a mailbox set up that you bcc each email to. That way you will have a copy of the email in your email program. When a customer replies to an email it will then get sent to your email account or the company email account depending on how it is configured within ServiceBox.