Rated 4 out of 5 stars

(Almost) perfect add-on :-) Thanks!! How can I add a date or datetime in the subject f.i. yymmdd or yymmdd hhmm, etc.

Léirmheas ar leagan níos sine den bhreiseán seo (0.0.2). 

Thanks for the feedback. Actually this was requested in the joplin forum too and is already available upstream (https://github.com/marph91/thunderbird-joplin-export/issues/11). I will try to submit a release this week. Until that it's only possible to refer the default date by using "{{date}}" in the note title setting.