Version: (using KDE 4.3.3) Testcase can be found here: https://bugs.kde.org/show_bug.cgi?id=214696 For example when KMail cannot open file when adding attachment the error says "file does not exist". This is bold and inaccurate statement -- the fact KMail cannot open file, the message should be "file cannot be read/opened (*)" (* one of those two). I just observed how puzzling current message is for users -- they see the file, so obviously file exists, yet another program (KMail) claims the file does not exist. It is very confusing and "of course" admin (me) is called because user cannot sort it out. And the reasons could be various -- bug in Kmail (as in testcase), -r for reading (!), and so on.
When I try to attach a file I have no read permission (either via selecting the file in the "Attach File" filedialog or via drag/drop, kmail tells me "Could not read xxx", which is correct. So it seems the problem only occurs with the file you mention in your other bug entry. So I'd say this one is simply a duplicate of #214696 *** This bug has been marked as a duplicate of bug 214696 ***