Version: (using KDE KDE 3.5.5) Such button would paste the data from selected message according to selected field. For "from" it would suggest "from", for "subject" -- "subject", and so on. It would be useful to create filters based on two fields (or more). Currently I have to look at the mail and type the second and rest of fields.
*** This bug has been marked as a duplicate of bug 55835 ***