spring - Java send email through gmail, sometimes works sometimes hang -

i sending email gmail through web app.

however, working fine stop without message.

does know how solve this?

in spring appconfig.java

@bean     public javamailsender getmailsender(){         javamailsenderimpl mailsender = new javamailsenderimpl();         mailsender.sethost("smtp.gmail.com");         mailsender.setport(587);         mailsender.setusername("my email from");         mailsender.setpassword("my email password");          properties javamailproperties = new properties();         javamailproperties.put("mail.smtp.starttls.enable", "true");         javamailproperties.put("mail.smtp.auth", "true");         //javamailproperties.put("mail.transport.protocol", "smtps");         javamailproperties.put("mail.transport.protocol", "smtp");         javamailproperties.put("mail.debug", "true");          mailsender.setjavamailproperties(javamailproperties);         return mailsender;     } 

in mailservice.java

public void sendemailwithtemplate(activity activity, object object) {         member member = (member) object;          mimemessagepreparator verificationemail = getemailfromactivity(activity, member);          try {             mailsender.send(verificationemail);             system.out.println("message sent.............................");         } catch (mailexception ex) {             system.err.println(ex.getmessage());         }     }  private mimemessagepreparator getemailfromactivity(final activity activity, final member member) {          mimemessagepreparator preparator = new mimemessagepreparator() {              public void prepare(mimemessage mimemessage) throws exception {                 mimemessagehelper helper = new mimemessagehelper(mimemessage, true);                  helper.setsubject(activity.getactivity_subject());                 helper.setfrom("my email");                 helper.setto(member.getemail());                  string mailcontent = activity.getactivity_content();                  helper.settext(mailcontent, true);               }         };         return preparator;     } 

sometimes working fine , able send mail, sometime stop more 20 minutes at:

debug smtp: enable sasl debug smtp: useehlo true, useauth false debug smtp: trying connect host "smtp.gmail.com", port 587, isssl false 

this method other post, can't post. activity 1 of object storing subject , content.

public void sendemailwithactivity(activity activity, object object, string path) {         try {             member member = (member) object;             string host = "smtp.gmail.com";             string username = "email";             string password = "password";             string body = activity.getactivity_content();             string name = activity.getactivity_name();             string subject = activity.getactivity_subject();=               //set properties             properties props = new properties();             props.put("mail.smtps.auth", "true");             // set session here             session session = session.getdefaultinstance(props);             mimemessage msg = new mimemessage(session);             // set message content here             msg.setsubject(subject);             msg.setcontent(body, "text/html");             msg.setfrom(new internetaddress(username));             msg.addrecipient(message.recipienttype.to,                     new internetaddress(member.getemail()));             transport t = session.gettransport("smtps");              t.connect(host, username, password);             t.sendmessage(msg, msg.getallrecipients());             t.close();         } catch (exception e) {             e.printstacktrace();         } {          }      }