Outbound Engine schedules the email campaigns to be released on the first and third full week of each month. You will be able to download a preview the Friday afternoon prior to each scheduled campaign.
You can also log into app.outboundengine.com and click on the Campaigns tab. On that tab, you will see a schedule of upcoming and past email campaigns.
You can view the details for each campaign by highlighting the campaign in question and clicking on the "Preview Email" link on the right hand side of the page. From this page you may also send yourself a test copy of the email campaign as well. Just highlight the campaign you are looking for and then click the "Send Test" button at the bottom of the page.