Error using JavaMail with Office365 account

I have a Java class that works perfectly for sending emails through a Gmail account. However, even using the recommended settings to send an SMTP email with Office365, an error is returned.

The error is as follows:

  

exception javax.servlet.ServletException: javax.mail.MessagingException: Could not connect to SMTP host: smtp.office365.com, port: 587; nested exception is: javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection?

Here is the code for my class:

public class GmailBean {

    public static final String SERVIDOR_SMTP = "smtp.office365.com";
    public static final int PORTA_SERVIDOR_SMTP = 587;
    private static final String CONTA_PADRAO = "[email protected]";
    private static final String SENHA_CONTA_PADRAO = "xxx";

    private String de;
    private String para;

    private String assunto;
    private String mensagem;

    public void enviarEmail() throws MessagingException {
        FacesContext context = FacesContext.getCurrentInstance();
        AutenticaUsuario autenticaUsuario = new AutenticaUsuario(GmailBean.CONTA_PADRAO, GmailBean.SENHA_CONTA_PADRAO);

        Session session = Session.getInstance(this.configuracaoEmail(), autenticaUsuario);

        // try{
        Transport envio = null;
        MimeMessage email = new MimeMessage(session);
        email.setRecipient(Message.RecipientType.TO, new InternetAddress(this.para));
        email.setFrom(new InternetAddress(this.de));
        email.setSubject(this.assunto);
        email.setContent(this.mensagem, "text/plain");
        email.setSentDate(new Date());
        envio = session.getTransport("smtp");
        envio.connect(GmailBean.SERVIDOR_SMTP, GmailBean.CONTA_PADRAO, GmailBean.SENHA_CONTA_PADRAO);
        email.saveChanges();
        envio.sendMessage(email, email.getAllRecipients());
        envio.close();

        context.addMessage(null, new FacesMessage("Mensagem enviada com sucesso!"));

        /* }
        catch(AddressException ex)
        { Logger logger = Logger.getAnonymousLogger();

        FacesMessage msg = new FacesMessage("Erro ao enviar mensagem "+ ex.getMessage());
        logger.info("Erro ao enviar mensagem _____________"+ ex.getMessage());
        }
        catch(MessagingException ex)
        {
        Logger logger = Logger.getAnonymousLogger();
        FacesMessage msg = new FacesMessage("Erro ao enviar mensagem "+ ex.getMessage());
        logger.info("Erro ao enviar mensagem _____________"+ ex.getMessage());

        }*/
    }

    public Properties configuracaoEmail() {
        Properties config = new Properties();

        config.put("mail.smtp.auth", "true");
        config.put("mail.transport.protocol", "smtp");
        config.put("mail.smtp.starttls.enabled", "true");
        config.put("mail.smtp.host", SERVIDOR_SMTP);
        config.put("mail.user", GmailBean.CONTA_PADRAO);
        config.put("mail.smtp.port", PORTA_SERVIDOR_SMTP);
        config.put("mail.smtp.socketFactory.port", PORTA_SERVIDOR_SMTP);
        config.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
        config.put("mail.smtp.socketFactory.fallback", "false");

        return config;
    }

    // getters and setters

    class AutenticaUsuario extends Authenticator {

        private String usuario;
        private String senha;

        public AutenticaUsuario(String usuario, String senha) {

            this.usuario = usuario;
            this.senha = senha;

        }

        public PasswordAuthentication getPasswordAuthentication() {
            return new PasswordAuthentication(this.usuario, this.senha);
        }

    }

}