Migrating PST files gives winmail.dat attachments

Hi,

after importing pst files from users with PST Capture, all attachments are converted into winmail.dat files. How is this possible? How can I solve this?

I've also started a thread on Office 365 for this, but for now we haven't found a solution: http://community.office365.com/en-us/forums/156/p/208395/641608.aspx#641608

Thank you.