https://bugzilla.redhat.com/783399 Last version where it worked: 3.7.10 It could be that this is related to the Gtk+ 3 port of mimeview.c, but there have been other changes in that file, too.
Oops, meant 3.7.10cvs83 (Port MimeView to GtkTreeView) not Gtk+ 3, of course.
Changes related to this bug have been committed. Please check latest CVS and update the bug accordingly. You can also get the patch from: http://www.claws-mail.org/tracker/ 2012-01-20 [pawel] 3.8.0cvs15 * src/mimeview.c Fix bug #2582 'Expanded mimeview drag n drop no longer works'
Fix confirmed.