0.9.18

mu

• Increase the default maximum size for messages to index to 500
  Mb; you can customize this using the --max-msg-size parameter to
  mu index.
• implement "lazy-checking", which makes mu not descend into
  subdirectories when the directory-timestamp is up to date;
  greatly speeds up indexing (see --lazy-check)
• prefer gpg2 for crypto
• fix a crash when running on OpenBSD
• fix --clear-links (broken filenames)

mu4e

reading messages

• Add mu4e-action-view-with-xwidget, and action for viewing
  e-mails inside a Webkit-widget inside emacs (requires emacs 25.x
  with xwidget/webkit/gtk3 support)
• Explicitly specify utf8 for external html viewing, so browsers
  can handle it correctly.
• Make `shr' the default renderer for rich-text emails (when
  available)
• Add a :user-agent field to the message-sexp (in mu4e-view), which
  is either the User-Agent or X-Mailer field, when present.

composing messages

• Cleanly handle early exits from message composition as well as
  while composing.
• Allow for resending existing messages, possibly editing them. M-x
  mu4e-compose-resend, or use the menu; no shortcut.
• Better handle the closing of separate compose frames
• Improved font-locking for the compose buffers, and more extensive
  checks for cited parts.
• automatically sign/encrypt replies to signed/encrypted messages
  (subject to `mu4e-compose-crypto-reply-policy')

searching & marking

• Add a hook mu4e-mark-execute-pre-hook, which is run just before
  executing marks.
• Just before executing any search, a hook-function
  mu4e-headers-search-hook is invoked, which receives the
  search expression as its parameter.
• In addition, there's a mu4e-headers-search-bookmark-hook which
  gets called when searches get invoked as a bookmark (note that
  mu4e-headers-search-hook will also be called just
  afterwards). This hook also receives the search expression as its
  parameter.
• Remove the 'z' keybinding for leaving the headers
  view. Keybindings are precious!
• Fix parentheses/precedence in narrowing search terms

indexing

• Allow for indexing in the background; see
  mu4e-index-update-in-background.
• Better handle mbsync output in the update buffer
• Add variables mu4e-index-cleanup and mu4e-index-lazy to enable
  lazy checking from mu4e; you can sit from mu4e using something
  like:

(setq
  mu4e-index-cleanup nil      ;; don't do a full cleanup check
  mu4e-index-lazy-check t)    ;; don't consider up-to-date dirs

misc

• don't overwrite global-mode-string, append to it.
• Make org-links (and more general, all users of
  mu4e-view-message-with-message-id) use a headers buffer, then
  view the message. This way, those linked message are just like
  any other, and can be deleted, moved etc.
• Support org-mode 9.x
• Improve file-name escaping, and make it support non-ascii filenames
• Attempt to jump to the same messages after a re-search update operation
• Add action for spam-filter options
• Let `mu4e~read-char-choice' become case-insensitive if there is
  no exact match; small convenience that affects most the
  single-char option-reading in mu4e.

Perl

• an experimental Perl binding ("mup") is available now. See
  perl/README.md for details.

Contributors:

Aaron LI, Abdo Roig-Maranges, Ævar Arnfjörð Bjarmason, Alex Bennée, Allen, Anders Johansson, Antoine Levitt, Arthur Lee, attila, Charles-H. Schulz, Christophe Troestler, Chunyang Xu, Dirk-Jan C. Binnema, Jakub Sitnicki, Josiah Schwab, jsrjenkins, Jun Hao, Klaus Holst, Lukas Fürmetz, Magnus Therning, Maximilian Matthe, Nicolas Richard, Piotr Trojanek, Prashant Sachdeva, Remco van 't Veer, Stephen Eglen, Stig Brautaset, Thierry Volpiatto, Thomas Moulia, Titus von der Malsburg, Yuri D'Elia

Getting the package

Download the official tarball.

Note, the below files are not complete releases, and require a full autotools setup. So, better pick the official one!