If you want to send emails from Revelation helpdesk using Search, you can select either To:, CC: or BCC: for the email addresses:
The selected emails will be shown in the appropriate area - To/CC/BCC - as selected. If you have an email template set up, you'll be able to select it from the drop down at the top of the email.
When emailing users from Search, Revelation helpdesk will authenticate the FROM email with the correct credentials as set up in the system. If the email is coming from a support staff account, Revelation will prompt for their email credentials.