You can’t send a mass email using a Visualforce email template.
<messaging:emailTemplate recipientType="Contact" relatedToType="Account" subject="Case report for Account: {!relatedTo.name}" language="{!recipient.language__c}" replyTo="support@acme.com"> <messaging:htmlEmailBody> <html> <body> <p>Dear {!recipient.name},</p> <p>Below is a list of cases related to {!relatedTo.name}.</p> <table border="0" > <tr> <th>Case Number</th><th>Origin</th> <th>Creator Email</th><th>Status</th> </tr> <apex:repeat var="cx" value="{!relatedTo.Cases}"> <tr> <td><a href = "https://na1.salesforce.com/{!cx.id}">{!cx.CaseNumber} </a></td> <td>{!cx.Origin}</td> <td>{!cx.Contact.email}</td> <td>{!cx.Status}</td> </tr> </apex:repeat> </table> <p/> <center> <apex:outputLink value="http://www.salesforce.com"> For more detailed information login to Salesforce.com </apex:outputLink> </center> </body> </html> </messaging:htmlEmailBody> </messaging:emailTemplate>