Come on, honestly: ESMTP (port 587) - possible or not?

Question

Hi all,
a special question to the ones invoked into JavaMail:
Is a connection to a ESMTP-server (port 587) possible with JavaMail? (And if yes - how?)
Certainly this is about sending mails via Gmail. And yes, I read http://java.sun.com/products/javamail/FAQ.html#gmail - and tested the demo-program. It works, but it turned out to use port 465. The problem is that Google advises its users to use port 587 und if you offer a webmail-client (which allows people to set a custom SMTP-port), these users will choose 587.
I read tons of howtos und code-examples and tried out dozens combinations of properties-settings and SMTPTransport-Connects, but I didn't succeed to send a message to Gmails server on port 587. The "best" I got was a "javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection?". Most of the time JavaMail tried to fallback and failured on port 25.
I feel like "shetline2" on this thread:
http://forum.java.sun.com/thread.jspa?forumID=43&threadID=706550
He faced exactly the same experiences like me. Unfortunately this thread ended without a solution.
And one more bonus-question:
Is it possible to determine "on-the-fly" which kind of "secure connection" the server expects? In my Thunderbird I found "TLS - if possible"!??
Thanks a lot for all hints and stuff!
Best regards
Stephan
This is to show that I wasn't to lazy to try out (all the commented lines were one      unsuccessful shot):
public static Session assembleJavaxMailSession(SmtpConnectionBean
smtpConnection) {
// Welches Protokoll?
String proto = smtpConnection.isSslConnection() ?
MailTransportProtocolEnum.SMTP_SSL.getProtocolId() :
MailTransportProtocolEnum.SMTP.getProtocolId();
// Properties holen und Werte aus der Bean setzen
Properties props = getProperties();
// props.setProperty("mail.transport.protocol", proto);
// props.setProperty("mail." + proto + ".host", smtpConnection.getSmtpHost());
// props.setProperty("mail." + proto + ".port", smtpConnection.getSmtpPort());
// props.setProperty("mail." + proto + ".quitwait", "false");
// // Bei SSL noch ein paar mehr Properties...
// if(smtpConnection.isSslConnection()) {
// props.setProperty("mail.smtps.socketFactory.class",
// "javax.net.ssl.SSLSocketFactory");
// props.setProperty("mail.smtps.socketFactory.port",
// smtpConnection.getSmtpPort());
// props.setProperty("mail.smtps.socketFactory.fallback", "false");
// props.setProperty("mail.smtps.starttls.enable","true");
props.setProperty("mail.smtp.host", smtpConnection.getSmtpHost());
props.setProperty("mail.smtp.port", smtpConnection.getSmtpPort());
// // SMTP-Auth?
// SmtpAuthenticator smtpAuthenticator = null;
// String smtpAuthUser = smtpConnection.getSmtpAuthUser();
// String smtpAuthPass = smtpConnection.getSmtpAuthPass();
// if((smtpAuthUser != null) && (smtpAuthPass.length() >= 1) &&
// (smtpAuthPass != null) && (smtpAuthPass.length() >= 1)) {
// smtpAuthenticator = new SmtpAuthenticator(smtpAuthUser, smtpAuthPass);
// // Authentifizierung erzwingen
// props.setProperty("mail." + proto + ".auth" , "true");
// Session session = Session.getInstance(props, smtpAuthenticator);
Session session = Session.getInstance(props, null);
// Just in case...
session.setDebug(true);
return(session);
// javax.mail.Session und MimeMessage erstellen
Session jms = JavamailUtils.assembleJavaxMailSession(smtpConnection);
MimeMessage mm = this.assembleMimeMessage(mailBasis, jms,
facesContext.getViewRoot().getLocale());
// Mail versenden
// // Der einfache Weg
// Transport.send(mm);
// // Der komplizierte Weg
// SMTPTransport transport =
// (SMTPTransport)jms.getTransport(smtpConnection.isSslConnection() ?
// MailTransportProtocolEnum.SMTP_SSL.getProtocolId() :
// MailTransportProtocolEnum.SMTP.getProtocolId());
// transport.setStartTLS(true);
// transport.connect(smtpConnection.getSmtpHost(),
// smtpConnection.getSmtpPortAsInt(),
// smtpConnection.getSmtpAuthUser(),
// smtpConnection.getSmtpAuthPass());
// transport.sendMessage(mm, mm.getAllRecipients());
// transport.close();
// Welches Protokoll?
String protocol = smtpConnection.isSslConnection() ?
MailTransportProtocolEnum.SMTP_SSL.getProtocolId() :
MailTransportProtocolEnum.SMTP.getProtocolId();
SMTPTransport transport = (SMTPTransport)jms.getTransport(protocol);
// SMTP-Auth?
String smtpAuthUser = smtpConnection.getSmtpAuthUser();
String smtpAuthPass = smtpConnection.getSmtpAuthPass();
if((smtpAuthUser != null) && (smtpAuthPass.length() >= 1) &&
(smtpAuthPass != null) && (smtpAuthPass.length() >= 1)) {
jms.getProperties().setProperty("mail." + protocol + ".auth", "true");
transport.connect(smtpConnection.getSmtpHost(),
smtpConnection.getSmtpPortAsInt(),
smtpConnection.getSmtpAuthUser(),
smtpConnection.getSmtpAuthPass());
else {
transport.connect();
transport.sendMessage(mm, mm.getAllRecipients());
transport.close();

Answer 1

I haven't evaluated all the details of the RFC 2476, but it works fine for me.
Use:
java -Dmail.smtp.starttls.enable=true -Dmail.smtp.port=587 smtpsend -A -d -M smtp.gmail.com -U user -P password ...You can't directly find out which type of connection the server expects,
but you can try the different connection types until one works.