Send mail to multiple recipients using multipart library in java

I want to send a message to multiple Recipients using below method:

But giving sendto = "test@test.co,Test2@test.co" giving error of invalid statement 'colon' used .

public void SendEmail(String content,String subject,String sendto) throws EmailException {        MultiPartEmail email = new MultiPartEmail();        email.setHostName("smtp.gmail.com");        email.setSmtpPort(465);         email.setAuthenticator(new DefaultAuthenticator(username, password));               email.setSSLOnConnect(true);        email.setFrom("Test");        email.setSubject(subject);        email.addTo(sendto);            email.setMsg(content);        System.out.println("Content Added");        email.setContent(content, "text/html; charset=utf-8");        email.send();        System.out.println("Email Sent");}