Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!gegeweb.org!de-l.enfer-du-nord.net!feeder1.enfer-du-nord.net!feeds.phibee-telecom.net!usenet.ukfsn.org!not-for-mail From: Martin Gregorie Newsgroups: comp.lang.java.programmer Subject: Re: JavaMail bug? Date: Fri, 29 Jul 2011 21:32:23 +0000 (UTC) Organization: UK Free Software Network Lines: 133 Message-ID: References: <995djcFq0nU1@mid.individual.net> NNTP-Posting-Host: 84.45.235.129 Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Trace: localhost.localdomain 1311975143 25481 84.45.235.129 (29 Jul 2011 21:32:23 GMT) X-Complaints-To: usenet@localhost.localdomain NNTP-Posting-Date: Fri, 29 Jul 2011 21:32:23 +0000 (UTC) User-Agent: Pan/0.133 (House of Butterflies) Xref: x330-a1.tempe.blueboxinc.net comp.lang.java.programmer:6668 On Mon, 25 Jul 2011 20:11:31 +0000, Martin Gregorie wrote: > I meant to add that I'm sorting out a bit of C at present. Running your > test program and extracting my SSCE it on the list behind it. > Sorted. Now back the the JavaMail problem: I modified the TestMail SSCE to suit my environment by changing the 'mail.smtp.host' property to "ukfsn.org" (my ISP) and the transport connect statement became tr.connect("zoogz.gregorie.org", "kiwi", "n/a") This works regardless of whether the local MTA is running or stopped. Then I made my own SSCE, MATestMail, from code in my mail dispatch class. The only differences between my SSCE and TestMail are that it does not add the 'mail.smtp.host' property to system props and it gets the session with "Session.getInstance(props)" rather than "Session.getDefaultInstance (props, null)". It also creates and sends a message to myself so the headers can be seen and I added a quick and dirty hack to optionally turn on SMTP debugging. Both turned out to be useful for working out exactly what was going on. The 'gotcha' turned out to be my omission to set the 'mail.smtp.host' property. I didn't do that because the connect() documentation says that it overrides the default host. This turns out to be incorrect: the MTA host named in connect() appears in all the debugging and is used by the getURL method, *but* the hostname supplied in the 'mail.smtp.host' property is what defines the MTA that is actually used. If the property is omitted the MTA host name defaults to localhost. When I added that property and messed about with its value I found the following behaviour, which was clearly shown by looking at the test message headers and the /var/log/maillog on zoogz: - With the 'mail.smtp.host' property unset the local MTA is always used: if its running the message is sent via 'localhost' and if it is stopped JavaMail reports a connection failure. - With it set to 'mail.ukfsn.org' the mail went via my ISP's mail server. - With it set to 'zoogz.gregorie.org' the mail is sent directly to zoogz. During all three property values the connect() method was using "zoogz.gregorie.org" as the 'host' parameter. For completeness, here's my SSCE: import java.util.Date; import java.util.Properties; import javax.mail.*; import javax.mail.internet.*; public class MATestMail { public static void main(String args[]) { String host = "zoogz.gregorie.org"; String user = "kiwi"; String password = "n/a"; String to = "martin@gregorie.org"; String from = "ma@gregorie.org"; String subject = "Test message"; boolean debug = true; Session sesh; try { Properties props = System.getProperties(); sesh = Session.getInstance(props); if (args.length > 0) sesh.setDebug(debug); MimeMessage msg = new MimeMessage(sesh); MimeMultipart body = new MimeMultipart(); InternetAddress[] recipients = {new InternetAddress(to)}; InternetAddress sender = new InternetAddress(from); msg.setFrom(sender); msg.setRecipients(Message.RecipientType.TO, recipients); msg.setSubject(subject); msg.setSentDate(new Date()); MimeBodyPart b = new MimeBodyPart(); b.setText("This is an SSCE test message\n"); body.addBodyPart(b); msg.setContent(body); msg.saveChanges(); Transport tr = sesh.getTransport("smtp"); tr.connect(host, user, password); System.out.println(tr); System.out.println(tr.getURLName()); tr.send(msg); tr.close(); } catch(MessagingException e) { e.printStackTrace(); } } } This SSCE doesn't set 'mail.smtp.host' and so will fail if the localhost MTA isn't running: I develop on a Linux box, so there's always a local MTA - hence the comment about the localhost MTA not running rather than it not existing. To make this SSCE connect directly to the target MTA (zoogz) I added the statement: props.put("mail.smtp.host", "zoogz.gregorie.org"); immediately after the 'Properties props = System.getProperties();' statement. The description of Transport.connect(host, user, password) is not at all clearly written, but having read it and the description of Transport.connect(user, password) I still think it means that the values supplied as connect() parameters should take precedence over those set via the property system, however connect() is plainly written to do the opposite, leaving me to wonder why connect(host, user, password) even exists. So, what do you think: have I found a bug? Many thanks to Nigel and Knute for helpful suggestions and example code. -- martin@ | Martin Gregorie gregorie. | Essex, UK org |