When using ZOHO.CAMPAIGNS to format and send email blasts to your CRM Leads/Contacts, you'll notice that you are required to submit all campaigns for approval before you can send them out. This is Zoho's way of making sure the content is appropriate. Before you are granted approval, your campaign is considered a Draft, and you are unable to send it anywhere.
Once you request and receive approval your email campaign is ready to go and you should see a Send button. If you don't, the most likely cause is that you clicked the Edit button AFTER you submitted the template for approval. Doing this negates the approval. Just submit it again and you should be good to go!