It's here: Hightail for Outlook
Bring the power of Hightail to your inbox. Access and share your Hightail folders from Outlook, send attachments larger than your Exchange server limit and automatically store attachments you receive in Hightail. For Microsoft Outlook 2007, 2010, and 2013 (32 and 64-bit). Windows Vista or higher.
For a complete list of installation FAQs, click here.