Access to "Share" blue button and "Send Mail" on a tools pane to set enabled proc for these buttons

For security reason I want to prevent attaching files to an email in some cases. I found three places where user are able to attach file to an email: File menu (share file menu item), tools pane (send email file tools item) and share blue button.

 For file menu item I can easyly set enabled proc for this menu item.

If I right click on a tools panel I'm able to hide this buttons so I suppose I'm able to do that from code.
I tried acquire panel from code like: AVAppGetToolBarByName("File"); becouse this item belongs to File section in rclick menu but I cannot asquire send email button : AVToolBarGetButtonByName(...).

I suppose that I got wrong toolbar.

What API should I use to get references for this buttons and as i'm able to set compute enabled proc for it?