Try the Thunderbird to Apple Mail Migration Tool that is very smart program to convert Thunderbird to Apple Mail quickly. The Thunderbird to Apple Mail conversion tool supports all version of Windows application - Windows XP, 7, 2000, Vista. You can purchase with full trust on Thunderbird into Apple Mail Migration Tool that is one and only perfect program to Convert Thunderbird to Apple Mail. This migration tool also save all attributes such as: attachments, Header information (to, subject, bcc, from, cc), formatting (font size, text size, color layout). The free Demo function is also provides by PCVARE. That function is capable for converting 10 Thunderbird files into Apple Mail. If you want complete conversion process then get the licensed key $99 to convert Thunderbird to Apple Mail.