4) setting change on "IMAP Account Options" (and not only here) don't trigger "Save Account" Button.
Clarified as follows:
On Accounts page "IMAP Account Options" all settings ("Use Gmail IMAP Extensions", "Use Server Spam Folder...", "Use Server Trash Folder") don't trigger "Save Account" button (after change button stay gray).
On Options page setting "Advanced Options" -> "Communicate using MAPI instead mailto" (after change button "Save Options" stay gray).
Save all off this options is possible only if i change other option on page.
Robo reports:
Clarified as follows: