As an administrator you want to be sure that all messages sent to crew are being read by them.
Panel Messages in Leon alerts if there is a new message - an icon is highlighted in yellow, however, it can happen that still that message is forwarded to crew member's work or personal email and is not read.
Now you can set that an email sent to crew by using panel 'Messages' - even if it is forwarded to the other email address - will appear without a content. So a crew member will have to enter Leon inbox to familiarize with it.
Go to section Admin > Operator Settings > General and in Leon inbox settings mark a checkbox 'Attach message content to Leon inbox mail notification'. Additionally, you can notify users if a new message arrives.
Such message will have no content - a recipient will have to go to 'Messages' in Leon to read it.
If the user clicks on the wrench-icon > messages he will see who the message was sent from, the subject and the date.