Log Message:
Update to 2.4.2:

* The recursive download of remote folders was enabled.
* The quick search condition for each folder now persists between sessions.
* The selection now persists when the quick search condition is updated.
* SSL ports in Advanced tab of the account prefs dialog are now automatically
  set when SSL is enabled.
* The '--open' command line option which open messages in new window was added.
* Quoted-printable or base64 encoding is now forced on PGP/MIME signing
  instead of stripping trailing spaces
  (except for the case of ISO-2022-JP encoding).
* The quoted-pair in From header is now processed correctly when displaying
  its name.
* The performance of 'Mark all read' on IMAP folders was improved.
* The bug that the character '+' in address was treated as URI-escaped
  space was fixed.
* Unix: the problem that 'Get' and 'Get all' button could not be clicked
  after receiving while mouse pointer was over the buttons was fixed.

2.4.1:

* If shift or control key is pressed on address completion, only address
  string is inserted now.