I encountered How can I set Dkim in phpmailer? recently. The correct answer is simply:
Oh, of course I might quote some parts of feature request on Drupal.org and describe with detail why it was moved from 6 to 7 branch, but it really looks like a material for commentary more than an answer. On the other hand, question seems legit, if not of high quality. No close reason really really fits.
So what should I do when I see questions like that?