Hi Srinivas,
You may try these easy steps to transfer the data:
1. Launch Microsoft Outlook.
2. Right-click Inbox and select "New Folder" from the context menu. Name the new folder, say EML.
3. Select the EML folder.
4. Select all the emails that you exported from Thunderbird by pressing "Ctrl-A".
5. Drag the emails drop them to the middle pane of Outlook to import them into the EML folder. The emails will appear in the folder after the import is complete.
Hope this helps.
Regards,
Steve Fan
TechNet Community Support