what if [callback]

javascript

this.sendMail = function(mailBody,maiSubject,mailTo, sendAt, callback){
  if(mailTo == 'string'){
      mailTo = formatMailTo(mailTo);
    }
    
    var message = {
        "html": mailBody,
        "text": mailBody,
        "subject": maiSubject,
        "from_email": "noreply@leilaodeonibus.com",
        "from_name": "Leilão de Ônibus",
        "to": mailTo
    };

    Mandrill.messages.send({"message": message, "async": false, "send_at": sendAt }, callback, callback);
};