Sending picture attachment in rich mail with debugmailplugin causes job to enter frozen state. The full error message is similar to:
VI.JobService.JobComponents.MailComponent - c3067672-eeaf-492f-b556-27a71de382db: Errors occured
[System.NullReferenceException] Object reference not set to an instance of an object.
at VI.JobService.ProcessorThread._ThreadFunction()
at VI.JobService.ProcessorThread._ExecuteJob(Job job)
at VI.JobService.JobComponents.MailComponent._SendRichMail()
at VI.JobService.JobComponents.MailCatcher.Catch(MailMessage message)
at VI.JobService.JobComponents.DebugMailPlugin.Handle(MailMessage message)
at VI.JobService.JobComponents.DebugMailPlugin._WriteMailAttachment(String filename, Attachment attachment)
at VI.JobService.JobComponents.DebugMailPlugin._MaskInvalidCharacters(String attName)