With Sylpheed, it is possible to drag a file to the
compose window to attach it, but it is not possible to
do the opposite, drag an attached file from a received
mail to a filer window.
Using ROX filer, trying to drag an attached file from
Sylpheed to ROX, I get the following error:
"uri_list_to_glist: Incorrect or missing line break in
Error getting file list: No URIs in the text/uri-list
(nothing to do!)"
I asked about this on the ROX list, and was pointed to
this page, indicating a possible bug in Sylpheed: