Hello, thanks for your help !
Unfortunately, I didn't quite understand how to resolve my problem with your instructions?
In /resources/views/emails/newPost.blade.php :
{!! $translator->trans('fof-follow-tags.email.body.newPostInTag', [
'recipient_display_name' => $user->display_name,
'actor_display_name' => $blueprint->post->user->display_name,
'discussion_title' => $blueprint->post->discussion->title,
'post_url' => $url->to('forum')->route('discussion', ['id' => $blueprint->post->discussion_id, 'near' => $blueprint->post->number]),
'post_content' => $blueprint->post->content,
]) !!}
What should I modify?
Edit : I simply modified the translation lines in the .yml file of my language pack (/vendor/flarum-lang/french/locale/fof-follow-tags.yml for me), everything is displayed correctly.