You might prefer to test your email in a "Live" send, rather than just a preview.
First create a relevant audience from your uploaded/integrated contacts, if you don't have one already, e.g: Just you and another member of your marketing team.
If you need help with creating a new audience, check out the How do I create an Audience? article.
You could also create a "Test" category in your CRM containing relevant emails and use this as your audience (bearing in mind sync times can be 2-3 hours).
From here, just create a campaign as you would any other*, selecting:
- Audience: e.g: Test Audience
- Scheduler: Date/Time - Schedule for now
- Send Email: Choose the email you want to send
- Click Save & Activate
* Jump over to the Create a Campaign article if you need help with this.