Ans - An easy method to add an Outlook PST file to Thunderbird:- 1. Open Outlook >> File >> Open & Export >> Import/Export. 2. Select Export to file >> Outlook Data File (.pst) >> choose the file and save it on the destination location. 3. Now, open Mac Outlook, Click File >> Import >> Outlook Data File (.pst). 4. Select Outlook for Windows Data File (.pst), save it in MBOX format, and drag & drop it to your desktop.