Stellar Data Recovery has released Stellar Mail Converter, an all-in-one email migration utility for Mac OS X. The tool is designed to help users migrate their emails from one platform to another.
You can convert mailboxes from Apple Mail, Thunderbird, PostBox and Outlook 2011 Backup File 2011 to Apple Mail and Outlook 2011. The converted mailboxes can be imported in Apple Mail/Outlook 2011 to view complete mail body, including attachments.
Stellar Mail Converter is available as try-before-you-buy software from Stellar Data Recovery online (http://www.stellarinfo.com/). This version will show you the preview of converted mails. To access all features, you must pay for the full version, which is being offered at an introductory price of US$39.