java - Set MessageId in header before sending mail -

i sending mails application using java mail on smtp server, port 465. need that, have set message-id before sending mail. did r&d , found code below. had override method updatemessageid() of mimemessage

import javax.mail.messagingexception; import javax.mail.session; import javax.mail.internet.mimemessage;  public class custommimemessage extends mimemessage {  public custommimemessage(session session) {     super(session); }  @override protected void updatemessageid() throws messagingexception {      setheader("message-id", "message id");     } } 

and had made instance of custommimemessage in service , invoke updatemessageid() method using instance, still message-id generated gmail.

in code

setheader("message-id", "message id"); 

you trying set "message id" message-id quite wrong have set unique id qualify rules of message id (read this).

try this..,.

import javax.mail.messagingexception; import javax.mail.session; import javax.mail.internet.internetaddress; import javax.mail.internet.mimemessage;  public class custommimemessage extends mimemessage { session session; private static int id = 0;  public custommimemessage(session session) {     super(session);     this.session=session; }  @override protected void updatemessageid() throws messagingexception {     setheader("message-id", "<" + getuniquemessageidvalue(session) + ">"); }  public static string getuniquemessageidvalue(session ssn) {     string suffix = null;      internetaddress addr = internetaddress.getlocaladdress(ssn);     if (addr != null)         suffix = addr.getaddress();     else {         suffix = "javamailuser@localhost"; // worst-case default     }      stringbuffer s = new stringbuffer();      // unique string <hashcode>.<id>.<currenttime>.javamail.<suffix>     s.append(s.hashcode()).append('.').append(getuniqueid()).append('.').       append(system.currenttimemillis()).append('.').       append("javamail.").       append(suffix);     return s.tostring();     }  private static synchronized int getuniqueid() {         return id++; } }