How to Convert Thunderbird to Mac Mail? If you feel the need to Convert Thunderbird to Mac Mail so that you can view EML emails into Mac Mail without any problems then tryout our software Thunderbird to Mac Mail program. It supports all windows operating system such as – Windows XP, Windows 2000, Windows7, Window 98 etc. Using this Conversion tool, users can get to successfully convert Thunderbird to Mac Mail MBOX while saving attachment. To Convert Thunderbird to Mac Mail you have to purchase this software first, also try the demo version of the software which can convert 10 emails free of cost.