This update for claws-mail fixes the following issues:

- Update to 4.3.1:
  * The configuration option, "Don't popup error dialog on receive error"
    has been changed to "Show error dialog on receive error". Your previous
    choice will be automatically changed to the new format.
  * The option "Warn when pasting files as attachments" has been added to
    the Compose/Writing preferences page. This option was previously
    hidden.
  * chmod 0600 is now set on *history files in the configuration directory.
  * A new preference has been added to enable setting the chmod value of
    saved attachments: "Save attachments with chmod [   ]", found on the
    Other/Miscelleanous preferences page. The default value is 600.
  * The creation and updating of .mh_sequences files in MH mailbox folders
    is now optional and disabled by default. This is controlled by a new
    hidden preference, mh_compat_mode. If you were previously relying on
    this feature, set mh_compat_mode=1 in clawsrc before running this
    version.
  * A new hidden preference has been added, passphrase_dialog_msg_title_switch.
    This switches the placement of the dialogue message with the dialogue
    title in the passphrase dialogue. This can be useful for interacting with
    third-party programs such as KeePassXC.
  * The top-level 'Mark' menu item has been renamed to 'Marks'. If you have
    set custom hotkeys for any items in this menu you will need to re-set
    them.
  * New accounts now have all secure options activated by default,
    including TLS connections and SMTP AUTH.
  * The option to accept valid TLS certificates is now activated by default
    on new accounts.
  * Notification plugin: support for Ayatana indicator has been added.
  * PDF Viewer plugin: support for image/x-eps (encapsulated postscript)
    images has been added.
  * Libravatar plugin: the https URL, https://seccdn.libravatar.org/avatar,
    is now used by default.
  * vCalendar plugin: CREATED/LAST_MODIFIED are correctly handled, and the
    VTIMEZONE component is used when present
  * Various code cleanups.
  * The English, Spanish and French manuals have been updated.
  * Updated translations: Albanian, Brazilian Portuguese, British English,
    Catalan, Czech, Dutch, French, Polish, Portuguese, Romanian, Russian,
    Simplified Chinese, Slovak, Spanish, Swedish, Turkish.
  * bug fixes:
    * bug 3964, 'Attachment icon doesn't show in message list unless
      the message is clicked and then disappears later'
    * bug 4658, 'Headers unfolded incorrectly in message view'
    * bug 4817, 'Edit button in Messages view->Text settings not
      translatable'
    * bug 4818, 'Your Claws Mail configuration is from a newer...'
      dialog is shown more than once'
    * bug 4819, 'Text wrapping broken when text contains an URL'
    * bug 4821, 'If the Mail folder is on another partition, folder
      chmod settings are not applied to draft and queue'
    * bug 4824, 'No syntax highlighting after exiting external editor'
    * bug 4828, '"Mark" not translated anymore'
    * bug 4835, 'Disallow a forward slash in (IMAP) account names'
    * bug 4840, 'core dump unsubscribing from newsgroups'
    * CID 1491093: attrib leaked if attvalue is null
    * CID 1491370: unchecked return value.
    * archive plugin build in debug mode.
    * keep newsgroup subscription window on top when 'subscribe to
      newsgroup...' fails and newsgroup list can't be retrieved
    * don't silently fail to save a sent msg
    * IMAP: show the clip icon in the message list as soon as
      possible
    * stop needlessly checking which folders want sycnhronising every
      time we select a msg in an MH mailbox

- Update to 4.3.0:
  * Compose window: when the focus is in the message text, copied files
    can be pasted as attachments using /Edit/paste or Ctrl+V.
    (The context menu's Paste will still insert the list of files into
    the message body.)
  * '/Mark/Mark all read in folder' and 'Mark/Mark all unread in
    folder' have been re-added to the Message List context menu.
  * It is now possible to use '/Tools/Remove references' when
    forwarding mail.
  * Keyboard shortcuts: The "Choose preset keyboard shortcuts" selector
    has been integrated into the main preferences page.
    When 'Current' is the selected preset, Apply/OK will keep the
    existing settings.
  * An MBOX file can now be imported from the command line using
    `claws-mail --import-mbox %f` where %f is the full path to the
    MBOX file.
  * OAUTH2 support for Microsoft 365 GCC High has been added.
  * LiteHTML Viewer plugin: Updated to LiteHTML 0.9.
  * The menurc file is now backed-up on startup.
  * Removed support for the obsolete Avant Window Navigator.
  * Various code cleanups.
  * The manual has been updated.
  * New translation: Albanian.
  * Updated translations: Catalan, Czech, French, Hungarian, Indonesian,
    Polish, Romanian, Slovak, Spanish, Swedish, Turkish.
  * bug 4668, 'Sometimes, at program start, message list takes
               all the vertical space'
  * bug 4720, 'matcher: release regex_t in
               matcherprop_string_match'
  * bug 4724, 'set proper availability status to sign/encrypt
               toolbar buttons'
  * bug 4725, 'oauth2: remove trailing zero from transmit
               buffer in oauth2_contact_server'
  * bug 4728, 'socket: handle GNUTLS_E_PREMATURE_TERMINATION in
               ssl_read'
  * bug 4730, 'oauth2: fix string handling in
               oauth2_contact_server'
  * bug 4733, 'Line breaks lost in headers'
  * bug 4734, 'ssl_certificate: remove unhelpful warnings from
               certificate check'
  * bug 4746, 'matcher: remove incorrect condition in
               matcherprop_free'
  * bug 4747, 'matcher: simplify matcherprop_new'
  * bug 4749, 'release regex_t in
               summary_compile_simplify_regexp'
  * bug 4750, 'remove regcomp wrapper and call regcomp
               directly'
  * bug 4752, 'Adjust incorrect debug_printf call in pgp
               plugins'
  * bug 4754, 'text/enriched literal less-than sign sequence
               handled incorrectly
  * bug 4757, 'remove AX_FUNC_MKDIR'
  * bug 4758, 'remove unused check for bind_textdomain_codeset'
  * bug 4759, 'remove unused function checks from
               AC_CHECK_FUNCS'
  * bug 4760, 'use correct type for move_bar_id'
  * bug 4762, 'oauth2: preserve an existing refresh token'
  * bug 4765, 'only store smtp auth if authorization method is
               OAUTH2'
  * bug 4766, 'preserve the expiry value of SMTP auth type is
               not OAUTH2'
  * bug 4768, 'Adjust logic while evaluating enable_avatars'
  * bug 4770, 'remove intl from list of include directories'
  * bug 4773, 'remove obsolescent AC_C_CONST'
  * bug 4780, 'use proper prototype for two archiver functions'
  * bug 4781, 'use correct prototype for
               privacy_free_signature_data'
  * bug 4782, 'use correct prototype for stop_archiving'
  * bug 4786, 'remove type confusion in getsockopt call in
               sock_connect_async_cb'
  * bug 4787, 'Use correct function for memory transfer in
               crypt_cfb_buf'
  * bug 4788, '"Change primary passphrase" disabled status
               handling'
  * bug 4790, 'widget spacing in "Changing primary passphrase"
               dialog'
  * bug 4791, 'remove obsolete glib version check'
  * bug 4795, 'Please remove -no-cpp-precomp flag for Apple'
  * bug 4796, 'URL with wide character doesn't work'
  * bug 4798, 'Quoting wrong when format=flowed and
               respect_flowed_format is set'
  * CIDs 1220325, 1491306 and 1491315, 'Explicit null
    dereferenced (FORWARD_NULL)'
  * CIDs 1491064, 1491074, 1491211, 1491105, 1491139, 1491164,
    1491166, 1491168, 1491169, 1491178, 1491232, 1491242,
    1492281 and 1591844 'Use after free (USE_AFTER_FREE)'
  * CID 1491137 'Out-of-bounds access (OVERRUN)'
  * CID 1591952 values overwritten before being used
  * CID 1596594 (CHECKED_RETURN)
  * CID 1596595 'Resource leak'
  * errors caused by invalid MIME viewer command-line
  * building on non-X11 systems
  * Use CFLAGS provided by nettle.pc
  * Fancy plugin, recognise mid and data embedded images