The digital forensics investigator has to face different email clients and email formats in their day to day life hence to make things convenient we are listing some of free software (100% Safe & Secure) that will aid in email forensic investigation.
If you have DBX format which is of Outlook Express origin then you can use the tool to view email, head information as well as attachments.
ZDB Viewer (Outlook Connected)
Many organizations connect their Zimbra Server with the Outlook email client using the Zimbra Add-on and this creates a ZDB file which holds all the information. You can use the application to view all the information that resides in it including the email head information.