Hello,
first thing to mention: Outlook has no easy (if any) option to store messages as .eml files. Standard and only build in is to store as .msg files. How did you obtain .eml files of your messages from Outlook?
- Import / Export is not transferring EML messages (Outlook).
mrb suggested to Drag & Drop the file direct onto the folder (e.g. Inbox) in Thunderbird. He was not suggesting to Import / Export something. Just to clarify, that this is not misunderstood.
Regards
Sehvornix