bug#8080: 24.0.50; Sending mail failed with Gmail/GnuTLS on Windows

[Christoph]

I use the following setup:

Emacs 24.0.50 r103346
GnuTLS 2.10.1 (from http://josefsson.org/gnutls4win/)
GnuGPG 1.4.11

running on Windows 7.

My mail setup is as follows:

(require 'smtpmail)
(setq send-mail-function 'smtpmail-send-it
      message-send-mail-function 'smtpmail-send-it
      smtpmail-starttls-credentials '(("smtp.gmail.com" 587 nil nil))
      smtpmail-auth-credentials (expand-file-name "~/.authinfo.gpg")
      smtpmail-default-smtp-server "smtp.gmail.com"
      smtpmail-smtp-server "smtp.gmail.com"
      smtpmail-smtp-service 587
      user-mail-address "xxx@gmail.com"
      smtpmail-debug-info t)

Sending a mail fails with the following error:

Sending via mail...
220 mx.google.com ESMTP ca7sm2512icb.12
250-mx.google.com at your service, [71.208.192.11]
250-SIZE 35651584
250-8BITMIME
250-STARTTLS
250 ENHANCEDSTATUSCODES
c:/Users/Christoph/A: 0% (0/105)
c:/Users/Christoph/A: 100% (105/105)
530 5.7.0 Must issue a STARTTLS command first. ca7sm2512icb.12
221 2.0.0 closing connection ca7sm2512icb.12
smtpmail-send-it: Sending failed; SMTP protocol error


The SMTP trace buffer contains this:

Process SMTP deleted
220 mx.google.com ESMTP ca7sm2512icb.12
EHLO MARVIN
250-mx.google.com at your service, [71.208.192.11]
250-SIZE 35651584
250-8BITMIME
250-STARTTLS
250 ENHANCEDSTATUSCODES
MAIL FROM:<xxx@gmail.com> SIZE=278
530 5.7.0 Must issue a STARTTLS command first. ca7sm2512icb.12
QUIT
221 2.0.0 closing connection ca7sm2512icb.12



In GNU Emacs 24.0.50.1 (i386-mingw-nt6.1.7600)
 of 2011-02-18 on MARVIN
Windowing system distributor `Microsoft Corp.', version 6.1.7600
configured using `configure --with-gcc (4.5) --cflags 
-IC:/Progra~2/GnuWin32/include -ID:/devel/emacs/libXpm-3.5.8/include 
-ID:/devel/emacs/libXpm-3.5.8/src'

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: ENU
  value of $XMODIFIERS: nil
  locale-coding-system: cp1252
  default enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  autopair-mode: t
  autopair-global-mode: t
  ido-everywhere: t
  yas/global-mode: t
  yas/minor-mode: t
  global-auto-revert-mode: t
  delete-selection-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  size-indication-mode: t
  column-number-mode: t
  line-number-mode: t

Recent input:
C-x RET r e p o r t <tab> <return>

Recent messages:
Loading c:/Users/Christoph/AppData/Roaming/.emacs.d/windows.el (source)...done
Loading c:/Users/Christoph/AppData/Roaming/.emacs.d/plugins.el (source)...
Ido mode enabled
Loading 
c:/Users/Christoph/AppData/Roaming/.emacs.d/anything-c-adaptive-history...done
Loading c:/Users/Christoph/AppData/Roaming/.emacs.d/plugins.el (source)...done
Loading c:/Users/Christoph/AppData/Roaming/.emacs.d/custom.el (source)...done
Loading c:/Users/Christoph/AppData/Roaming/.emacs.d/gnus.el (source)...done
Loading c:/Users/Christoph/AppData/Roaming/.emacs.d/init-custom.el 
(source)...done
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
~/.emacs.d/plugins/python hides 
d:/devel/emacs/emacs-bzr/trunk/lisp/progmodes/python

Features:
(shadow sort gnus-cite mail-extr gnus-msg gnus-art mm-uu mml2015
epg-config mm-view mml-smime smime dig mailcap nnir gnus-sum macroexp
nnoo gnus-group gnus-undo nnmail mail-source format-spec gnus-start
gnus-spec gnus-int gnus-range gnus-win message rfc822 mml mml-sec
mm-decode mm-bodies mm-encode mail-parse rfc2231 rfc2047 rfc2045
ietf-drums mailabbrev gmm-utils mailheader gnus gnus-ems nnheader
mail-utils wid-edit emacsbug url-util url-parse auth-source netrc
gnus-util time-date password-cache url-vars mm-util mail-prsvr
js2-mode-autoloads package zenburn-theme sha1 hex-util re-builder
ibuffer nav nav-tags nav-bufs uniquify anything-config warnings
browse-url semantic/util-modes semantic/util semantic semantic/tag
semantic/lex semantic/fw loaddefs eieio byte-opt bytecomp byte-compile
mode-local cedet imenu bookmark pp dired ffap thingatpt anything python
rx noutline outline ansi-color autopair google-c-style cc-mode cc-fonts
cc-menus cc-cmds cc-styles cc-align cc-engine cc-vars cc-defs
grep-o-matic grep compile comint regexp-opt browse-kill-ring+
browse-kill-ring second-sel ido yasnippet dropdown-list derived
easy-mmode easymenu assoc cl etags-table edmacro kmacro etags ring
org-install server advice help-fns advice-preload autorevert delsel
tooltip ediff-hook vc-hooks lisp-float-type mwheel dos-w32 disp-table
ls-lisp w32-win w32-vars tool-bar dnd fontset image fringe lisp-mode
register page menu-bar rfn-eshadow timer select scroll-bar mouse
jit-lock font-lock syntax facemenu font-core frame cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese case-table epa-hook jka-cmpr-hook help simple abbrev
button minibuffer faces cus-face files text-properties overlay md5
base64 format env code-pages mule custom widget hashtable-print-readable
backquote make-network-process multi-tty emacs)