JavaSendMailer throws NPE when no e-mail address configured for report

Steps to reproduce:

1. Ensure that an SMTP MTA is listening on 127.0.0.1. It need not be capable of actually delivery, only of completing a basic EHLO / NOOP / QUIT conversation.

2. Edit reportd-configuration.xml to run a known-working report with no recipients specified. The following works for me (note this results in a report being run every minute, so remember to turn it off):

<report report-name="sample-report" report-template="Early-Morning-Report.jrxml" report-engine="jdbc">
<cron-schedule>0 * * * * ? *</cron-schedule>
</report>

3. Reload Reportd's configuration:

send-event.pl uei.opennms.org/internal/reloadDaemonConfig -p 'daemonName Reportd'

4. Watch the event list and reportd.log

Expected result: everything pretty cool since we didn't ask for any e-mail delivery on this report
Actual result:

A. An event with UEI uei.opennms.org/reportd/reportDeliveryFailed and log message "The report with name sample-report could not be delivered for the following reason: Caught unexpected java.lang.NullPointerException: null"

B. An exception stack trace in reportd.log like the following:

2012-11-27 10:43:00,203 ERROR [reportd_Worker-8] JavaMailDeliveryService: Unexpected exception: null
java.lang.NullPointerException
at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:599)
at org.opennms.javamail.JavaSendMailer.send(JavaSendMailer.java:271)
at org.opennms.javamail.JavaSendMailer.send(JavaSendMailer.java:247)
at org.opennms.netmgt.reporting.service.JavaMailDeliveryService.deliverReport(JavaMailDeliveryService.java:75)
at org.opennms.netmgt.reporting.service.Reportd.runReport(Reportd.java:114)
at org.opennms.netmgt.reporting.service.ReportJob.execute(ReportJob.java:54)
at org.quartz.core.JobRunShell.run(JobRunShell.java:202)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:525)