User of mailer 1.5 + maven-plugin 2.0 reported an NPE.
java.lang.NullPointerException
	at java.util.StringTokenizer.<init>(StringTokenizer.java:199)
	at java.util.StringTokenizer.<init>(StringTokenizer.java:236)
	at hudson.tasks.MailSender.createEmptyMail(MailSender.java:326)
	at hudson.tasks.MailSender.createUnstableMail(MailSender.java:186)
	at hudson.tasks.MailSender.getMail(MailSender.java:160)
	at hudson.tasks.MailSender.execute(MailSender.java:100)
	at hudson.maven.reporters.MavenMailer.end(MavenMailer.java:56)
	at hudson.maven.AbstractMavenBuilder.end(AbstractMavenBuilder.java:103)
	at hudson.maven.MavenModuleSetBuild$MavenModuleSetBuildExecution.doRun(MavenModuleSetBuild.java:829)
	at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:566)
	at hudson.model.Run.execute(Run.java:1677)
	at hudson.maven.MavenModuleSetBuild.run(MavenModuleSetBuild.java:509)
	at hudson.model.ResourceController.execute(ResourceController.java:88)
	at hudson.model.Executor.run(Executor.java:231)