In Mountain Lion’s Mail app, I can delete attachments from mails others have sent me, but not from the mails I sent to others.
In the mailbox, the messages I have sent are not marked with the small paperclip, even when then have a attachments (however, their size is correct and includes the big attachments). When I select an individual message (or many), the "Delete attachements" menu item is grayed out.
How can I deleted attachments from mails I sent?