If the destination email address contains a valid domain but a bad account (BadAccount@ValidDomain.com), then the bounce back message would be sent from the destination mail server (mail@ValidDomain.com).
If the destination email address contains an invalid domain (Account@InvalidDomain.com), the bounce back message would be from the outgoing mail server. The outgoing mail server is determined by the settings found in Preferences > General Settings > Email.
If Pressero tried to send the message and the outgoing mail server rejected it, then this should show in Pressero admin area. However, if the outgoing mail server accepted it, we will not receive a bounce back message. In this case, we cannot show the bounce back message since we actually never received the bounce back message.