Kohei Nozaki's blog 

Configuring helo names of James


Posted on Friday Feb 06, 2015 at 04:47PM in Technology


My James instance looks like failed to determine its hostname as follows:

$ telnet localhost 10025
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
220 localhost.localdomain JAMES SMTP Server Server (JAMES SMTP Server ) ready
helo example.com
250 localhost.localdomain Hello example.com [127.0.0.1])

This can be solved by editing XML files such as smtpserver.xml, pop3server.xml and imapserver.xml respectively as follows:

<helloName autodetect="false">www.nailedtothex.org</helloName>

Also you should check that the name which James will use during communicate to another SMTP server. you can check it easily with this site. if the name is wrong, this may be a cause of that remote server will consider your James server as spammer. the name to use will be hostname of the server. you can check it with simply issuing hostname command on Linux.

Unfortunately you can’t set the hostname in portable way due to a bug in a dependency geronimo-javamail_1.4_mail. the hostname should be able to configured in mailetcontainer.xml as follows but not worked at the present time.

<!-- Set the HELO/EHLO name to use when connectiong to remote SMTP-Server -->
<mail.smtp.localhost>www.nailedtothex.org</mail.smtp.localhost>

So current geronimo-javamail_1.4_mail ignores that value. considerable solutions are following:

  1. Change the hostname of the server (for <= Java 7u51)

  2. Put you FQDN first (before localhost) in /etc/hosts. detail (for recent Java)

  3. Apply a patch to James

  4. Apply a patch to Geronimo JavaMail and update dependency of James. unfortunately seems like that fixed version of Geronimo JavaMail is not released yet.


Disabling SpamAssassin on James


Posted on Friday Feb 06, 2015 at 03:00PM in Technology


I’m using revision number 1657019 in the SVN trunk of James3. I see an error in james-server.log at every receiving of emails as follows:

INFO  14:41:51,912 | james.mailetcontext | Error communicating with spamd on localhost:783 Exception: java.net.ConnectException: Connection refused

It seems like that James is trying to connect to local SpamAssassin instance, but I have no SpamAssassin instance on my server yet so I simply deleted following definition from mailetcontainer.xml.

<mailet notmatch="SenderHostIsLocal" class="SpamAssassin">
  <spamdHost>localhost</spamdHost>
  <spamdPort>783</spamdPort>
</mailet>

Now the exception disappeared.


Defining aliases on James


Posted on Friday Feb 06, 2015 at 02:47PM in Technology


I’m using James3 in SVN trunk revision number 1657019.

Adding a user to recipient rewrite table

This forwards a address postmaster@example.com to kyle@example.com:

./james-cli.sh -p 9999 -h localhost addaddressmapping postmaster example.com kyle@example.com

Defining postmaster address

James replaces a particular address postmaster by PostmasterAlias according to XML definition on some environment, so we need to set correct email address to it. in $JAMES_HOME/mailetcontainer.xml as follows:

<mailetcontainer enableJmx="true">

    <!-- MailAddress used for PostMaster -->
        <context>
            <postmaster>kyle@example.com</postmaster>
        </context>
...


Updating and Configuring Derby shipped with James


Posted on Friday Feb 06, 2015 at 02:30PM in Technology


Put latest Derby jars

I used derby.jar and derbynet.jar of 10.11.1.1 to accept network connections. put these jars you needed into $JAMES_HOME/lib.

Define that jars to wrapper.conf

Comment out following line in $JAMES_HOME/conf/wrapper.conf:

#wrapper.java.classpath.94=%REPO_DIR%/derby-10.9.1.0.jar

Then put following line:

wrapper.java.classpath.94=%REPO_DIR%/derby.jar

Make Derby to accept network connections

Add following line to $JAMES_HOME/conf/wrapper.conf.

wrapper.java.classpath.131=%REPO_DIR%/derbynet.jar

Also additional system properties are needed:

wrapper.java.additional.15=-Dderby.drda.startNetworkServer=true
wrapper.java.additional.16=-Dderby.drda.portNumber=11527

Config derby.log

I prefer to place derby.log into $JAMES_HOME/log, and append log to exist one.

wrapper.java.additional.17=-Dderby.stream.error.file=../log/derby.log
wrapper.java.additional.18=-Dderby.infolog.append=true

Define shutdown hook of Derby

Lob streaming is not supported

Currently OpenJPA, James’s JPA provider, is not supported lob streaming for Derby. James stored mail data in lob so If you frequently use larger mails, consider using other databases instead of Derby.


Profiling remote JVM over SSH with VisualVM


Posted on Friday Feb 06, 2015 at 01:31PM in Technology


UPDATE October 2015: This procedure requires a VisualVM distribution that can be obtained from https://visualvm.java.net . At least, It will work with VisualVM 1.3.8. May doesn’t work with VisualVM which has been installed as a part of JDK distribution. I have experienced VisualVM which comes with JDK8u60 doesn’t work.

First I tried that creating a tunnel like ssh remote.example.org -L 19999:localhost:9999 and connecting VisualVM to localhost:19999, but it didn’t worked. intead, creating a socks tunnel like ssh remote.example.com -D 1080 and connecting VisualVM to localhost:9999 via socks proxy is worked. detailed procedure is following:

  1. Create ssh socks tunnel

  2. Set manual proxy in VisualVM’s preferences

  3. Right-click Local

  4. Add JMX connection

  5. Enter localhost:9999 to text box

  6. Click OK

  7. Double-click newly added JMX icon

Make sure that destination JVM has started with following system properties:

-Dcom.sun.management.jmxremote=true
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.port=9999
-Dcom.sun.management.jmxremote.ssl=false