SMTP email configuration exception

report.scheduler.mail.sender.host=smtp.gmail.com
report.scheduler.mail.sender.username=xxx
report.scheduler.mail.sender.password=xxx
report.scheduler.mail.sender.from=xxx
report.scheduler.mail.sender.protocol=smtp
report.scheduler.mail.sender.port=587
 
report.scheduler.web.deployment.uri=http://ipaddress:8084/jasperserver

2014-11-07 11:12:41,568 ERROR ReportExecutionJob,quartzScheduler_Worker-1:306 - The job error notification was not completed. An error occurred while sending it.
java.lang.NullPointerException
    at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:557)
    at org.springframework.mail.javamail.JavaMailSenderImpl.doSend(JavaMailSenderImpl.java:416)
    at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:340)
    at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:336)
    at com.jaspersoft.jasperserver.api.engine.scheduling.quartz.ReportExecutionJobMailNotificationImpl.sendMailNotification(ReportExecutionJobMailNotificationImpl.java:123)
    at com.jaspersoft.jasperserver.api.engine.scheduling.quartz.ReportExecutionJob.sendMailNotification(ReportExecutionJob.java:931)
    at com.jaspersoft.jasperserver.api.engine.scheduling.quartz.ReportExecutionJob.executeAndSendReport(ReportExecutionJob.java:526)
    at com.jaspersoft.jasperserver.api.engine.scheduling.quartz.ReportExecutionJob.execute(ReportExecutionJob.java:217)
    at org.quartz.core.JobRunShell.run(JobRunShell.java:213)
    at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:557)