Erro: Sending the email to the following server failed : smtp.gmail.com:465

Programação Java
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#1 
public Mail(Avaliacao av, ArrayList<Avaliacao> avs,String titlo){
        t = new Thread(){
            @Override
            public void run(){
                System.out.println("Inicou");
                
                //Separa os itens da informaçao do sender
                String email = av.email;
                String title = titlo;
                String filename = "doc.pdf";
                
                //Loga no email do sender
                String Email = "email";
                String Senha = "senha";
                
                //Loga no smtp do email
                MultiPartEmail mail = new MultiPartEmail();
                mail.setHostName("smtp.gmail.com");
                mail.setSmtpPort(465);
                mail.setAuthentication(Email, Senha);
                mail.setSSLOnConnect(true);
        
                try {
                    
                    mail.setFrom(Email);
                    mail.addTo(email);
                    mail.setSubject(title);
            
                    File file = new File(filename);
                    EmailAttachment attachment = new EmailAttachment();
                    attachment.setPath(file.getPath());
                    attachment.setName(file.getName());
                    mail.attach(attachment);
                    mail.send();
                } catch (Exception e) {
                    System.out.println(e);
                }
                stop();
            }   
        };
    }