Rated 1 out of 5 stars

Experience with ImportExportTools (IET):
E-Mails exported from mail-folders in Mbox-Files.
New Installation of Thunderbird.
Attempt to reimport mails with IET fails with message:
"Reimport to this folder is not possible:
Probably it is a folder of an IMAP-account or a newsgroup".
In fact it is the same folder from which the mails were exported.
Effect of application or IET: Loss of all exported mails!

Léirmheas ar leagan níos sine den bhreiseán seo (10.0.4).  Rinne an t-úsáideoir seo léirmheas ar an mbreiseán seo cheana.

U
please post any issue in the repository:
https://github.com/thundernest/import-export-tools-ng/issues
I think you need some help understanding the use of the extension. if you exported successfully you have not lost any.