Having a .msg attachment or Content-Type: multipart/alternative will not create mail issue, NullPointerException in log file.

Summary:

An e-mail that is send to the JIRA Service Desk e-mail channel will fail if the e-mail has another e-mail attached to it in the .msg format. This occurs on windows with Service Desk 2.3.5.

Steps to Reproduce:

1. Save an e-mail and attach it to another e-mail
2. Send this message with the attached e-mail to the e-mail channel

Expected Results:

Issue is created from e-mail

Actual Results:

Error is thrown in atlassian-jira-incoming-mail.log:

2015-04-17 21:31:39,416 ERROR [] atlassian-scheduler-quartz1.clustered_Worker-3 anonymous     Exception when MailHandlerWorker handles message: 
java.lang.NullPointerException
	at javax.mail.internet.MimeUtility.decodeText(MimeUtility.java:573)
	at com.atlassian.servicedesk.squalor.email.ServiceDeskMailUtils.addAttachments(ServiceDeskMailUtils.java:310)
	at com.atlassian.servicedesk.squalor.email.ServiceDeskMailUtils.getAttachments(ServiceDeskMailUtils.java:260)

Notes:

• The message we have tested it with had a nested attachment (xls format) within the attached e-mail .msg file.
• The same error also happens with .eml as attached files
• The problem seems to be more related with the email client being used than the message attached. From the tests, the problem happens only with Outlook and does not happen with Gmail and the Mac OS X Mail client.
• The same error will happens as well for Email that is coming from Open Technology Real Service(OTRS). OTRS Email Settings
• The same behaviour also occurs when using Novel Groupwise and both e-mails are from the same domain and this can be avoided using POP instead of IMAP.
• Another one confirmed for an email that is coming from IBM Notes 9.
• Airmail is also confirmed having the same error.
• Zarafa is confirmed having the same error.