I was able to left click and email, drag it to the QF tab I wanted and a list
of the sub folders would appear and I could move the email to the sub-folder I
wanted.  Now, when I drag any email to any QF tab, I do not get the drop-down
list of sub-folders and can not move the email.

As it looked like a regression from my point of view I submitted a bug for
Thunderbird: 

https://bugzilla.mozilla.org/show_bug.cgi?id=1268474

Created an attachment (id=8183) [details]
4.4.3 prerelease 43

SFixes the issue for he following cases:

1) dragging an email to a tab to move it
2) dragging an email to a tab and subfolder from a popup
3) dragging an email to a tab and "new Subfolder..." via popup menu


Apparently the "dragSession" in the drop event doesn't contain the necessary
information anymore so I am getting it from event.dropData instead. Tested in
Tb Release (45) and Daily (48.0a2 (2016-05-08))

Needs to be regression tested against SeaMonkey and Postbox!

Solution Works in Postbox 4.0. To do: test in SeaMonkey.

Release 4.5 - Resolved Fixed

Need to reopen this bug.  Drag and drop to either copy or move does not work in
ver. 4.5 of QF when using Daily 50.0a1 dated 07-27-2016. This time though, the
subfolders will appear when hovering over a QF tab.

Reopening for Tb Daily 50. Probably another regression caused by more changes
in the mozilla-central (Firefox) platform code.

Created an attachment (id=8236) [details]
QF 4.5 prerelease 65

the dragdrop event in Mozilla was renamed to drop, see 

https://bugzilla.mozilla.org/show_bug.cgi?id=1162050

This should affect both dragging emails and folders. This version fixes the
problem by using the new event name.

(In reply to comment #7)
> Created an attachment (id=8236) [details] [details]
> QF 4.5 prerelease 65

Hm, QF 4.5 has already been released (on or before 25 July). Shouldn't this be
4.5.1pre65 or 4.6pre1, or anything _higher_ than 4.5?

(From update of attachment 8236 [details])
title was wrong, 4.6 obviously

(In reply to comment #8)
> (In reply to comment #7)
> > Created an attachment (id=8236) [details] [details] [details]
> > QF 4.5 prerelease 65
> 
> Hm, QF 4.5 has already been released (on or before 25 July). Shouldn't this be
> 4.5.1pre65 or 4.6pre1, or anything _higher_ than 4.5?
> 

Right on. Just a typo. 4.6 it is.

Features
## Support copying and pasting the folder tabs definitions in order to edit
them in a text editor.
## Support for Postbox 5
## Made coloring + styling (flat style) more reliable in SeaMonkey (WIP)
## Platform modernization: replaced old dragdrop events with drop events.

Resolved in Release 4.6