I was looking at a similar report on sumo and found that my Windows 10
didn't open Thunderbird - in fact, didn't do anything. On investigation,
the "send to" item pointed to "Mail", despite Thunderbird being set as
the system default email application. Is "Mail" intended to map to the
default email client? Or is it the specific name of a Microsoft client?
Following advice found on
superuser.com, I created a specific
Thunderbird shortcut item for the sendto menu and now it works as well
as can be expected. A document or file can be right-clicked, Thunderbird
selected, and Thunderbird opens a composition window with the file
attached.
It doesn't seem to accept more than one filename to be attached. Only
one of the selected files appears in Thunderbird's attachments window.
https://superuser.com/questions/906463/adding-to-sendto-context-menu-in-windows-10
Interestingly, this article:
http://kb.mozillazine.org/Command_line_arguments_(Thunderbird) only
discusses how to add one attachment; there is no hint of how one could
or should concatenate several attachments' names.
--
Chris