NullPointerException in SubscriptionMailQueueItem.sendSearchRequestEmail

Every time the mail is send, we get the following error in catalina.out:
2005-01-13 11:10:29,766 ERROR [atlassian.jira.mail.SubscriptionMailQueueItem]
java.lang.NullPointerException
at com.atlassian.jira.mail.SubscriptionMailQueueItem.sendSearchRequestEmail(SubscriptionMailQueueIte
m.java:86)
at com.atlassian.jira.mail.SubscriptionMailQueueItem.send(SubscriptionMailQueueItem.java:64)
at com.atlassian.mail.queue.MailQueueImpl.sendBuffer(MailQueueImpl.java:55)
at com.atlassian.jira.service.services.mail.MailQueueService.run(MailQueueService.java:23)
at com.atlassian.jira.service.JiraServiceContainer.run(JiraServiceContainer.java:53)
at com.atlassian.jira.service.ServiceRunner.execute(ServiceRunner.java:50)
at org.quartz.core.JobRunShell.run(JobRunShell.java:147)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:387)
2005-01-13 11:10:29,766 ERROR [atlassian.mail.queue.MailQueueImpl] com.atlassian.mail.MailException
java.lang.NullPointerException
at com.atlassian.jira.mail.SubscriptionMailQueueItem.sendSearchRequestEmail(SubscriptionMailQueueIte
m.java:86)
at com.atlassian.jira.mail.SubscriptionMailQueueItem.send(SubscriptionMailQueueItem.java:64)
at com.atlassian.mail.queue.MailQueueImpl.sendBuffer(MailQueueImpl.java:55)
at com.atlassian.jira.service.services.mail.MailQueueService.run(MailQueueService.java:23)
at com.atlassian.jira.service.JiraServiceContainer.run(JiraServiceContainer.java:53)
at com.atlassian.jira.service.ServiceRunner.execute(ServiceRunner.java:50)
at org.quartz.core.JobRunShell.run(JobRunShell.java:147)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:387)
2005-01-13 11:12:29,757 ERROR [atlassian.jira.mail.SubscriptionMailQueueItem]
java.lang.NullPointerException
at com.atlassian.jira.mail.SubscriptionMailQueueItem.sendSearchRequestEmail(SubscriptionMailQueueIte
m.java:86)
at com.atlassian.jira.mail.SubscriptionMailQueueItem.send(SubscriptionMailQueueItem.java:64)
at com.atlassian.mail.queue.MailQueueImpl.sendBuffer(MailQueueImpl.java:55)
at com.atlassian.jira.service.services.mail.MailQueueService.run(MailQueueService.java:23)
at com.atlassian.jira.service.JiraServiceContainer.run(JiraServiceContainer.java:53)
at com.atlassian.jira.service.ServiceRunner.execute(ServiceRunner.java:50)
at org.quartz.core.JobRunShell.run(JobRunShell.java:147)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:387)
2005-01-13 11:12:29,757 ERROR [atlassian.mail.queue.MailQueueImpl] com.atlassian.mail.MailException