javax.mail.MessagingException: 530 5.7.0 Must issue a STARTTLS command first

javax.mail.MessagingException: 530 5.7.0 Must issue a STARTTLS command first. u12sm73042tia.38

    at com.sun.mail.smtp.SMTPTransport.issueCommand(SMTPTransport.java:879)
    at com.sun.mail.smtp.SMTPTransport.mailFrom(SMTPTransport.java:599)
    at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:319)
    at com.roadway.edmail.util.JMail2.sendMail(JMail2.java:278)
    at com.roadway.edmail.bo.feedback.FeedbackSender.sender(FeedbackSender.java:72)
    at org.apache.jsp.test_jsp._jspService(test_jsp.java:59)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at com.roadway.edmail.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:20)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.tuckey.web.filters.urlrewrite.RuleChain.handleRewrite(RuleChain.java:164)
    at org.tuckey.web.filters.urlrewrite.RuleChain.doRules(RuleChain.java:141)
    at org.tuckey.web.filters.urlrewrite.UrlRewriter.processRequest(UrlRewriter.java:90)
    at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:417)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:286)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:845)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
    at java.lang.Thread.run(Thread.java:619)

解决方案：
if(this.smtp.indexOf("smtp.gmail.com")>=0)
            {
                properties.setProperty("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
                properties.setProperty("mail.smtp.socketFactory.fallback", "false");
                properties.setProperty("mail.smtp.port", "465");
                properties.setProperty("mail.smtp.socketFactory.port", "465");
            }