Yes, if the user is a fast clicker perhaps this causes an issue.
The idea is to add only the selected files to the new mail. So the selection is important, but folders shall be ignored.
Ah, but your proposal leads to the solution with cmd.AddFiles(tab.selected_files):
cmd.ClearFiles();
cmd.AddFiles(tab.selected_files)
To keep it "in mind", but not necessary I think:
An alternative would be to use an enumerator like I did it in my first request regarding thunderbird mails. But I found a code from you which seems to be a little bit better then mine - I have to take a deeper look if it is relevant some day: {allfilepath} - Changing separetor between each file - #7 by Leo