Log Message:
Update to 2.4.8:

* The encoding method of MIME headers is now determined by outgoing
  encoding rather than the value of MB_CUR_MAX.
* The memory leaks and warnings in LDAP search were fixed.
* The beep on folders with one message when using GTK+ 2.12 was removed.
* Win32: The crash that occurred when trying to display some TIFF files was fixed.
* Win32: Settings are now automatically saved on the shutdown of system.