bug#40012: 26.3; Sending Mail to Recipient without public key

[passt mu4e1]

I configured to encrypt all outgoing mail via customize. When I try to
send an email to a recipient, from which I don't have a public key, I'm
getting asked, if I wan't to skip it. If I confirm, I'm getting the
error-message: mml-secure-recipients: No recipient specified. My
expectation would have been, that I send the mail unencrypted.

If I have multiple multiple recipients and I don't have the key from one
of them, I'm getting asked again wether I want to skip the recipient. If
I accept, he gets a weird message with the following contents:

Attachment: [1. application/pgp-encrypted]...

[[PGP Encrypted Part:Failed]]
[1. application/pgp-encrypted]...

[[End of PGP Encrypted Part]]



The other recipients get a normal encrypted email.



In GNU Emacs 26.3 (build 5, x86_64-pc-linux-gnu, GTK+ Version 3.24.12)
 of 2020-02-23 built on laptop
Windowing system distributor 'The X.Org Foundation', version 11.0.12005000
System Description:     Ubuntu 19.10

Recent messages:
Mark set
Saving file 
/home/mm/Mail/mu4e1/Drafts/cur/1583831476.8a33d52a100310d0.laptop:2,DS...
Mark set
Wrote /home/mm/Mail/mu4e1/Drafts/cur/1583831476.8a33d52a100310d0.laptop:2,DS
[mu4e] Saved (10 lines)
Sending...
Mark set [2 times]
No encrypt key for <passtmu4e2@outlook.com>; skip it? (y or n) y
mml-secure-recipients: No recipient specified

Configured using:
 'configure --with-modules --with-xml2'

Configured features:
XPM JPEG TIFF GIF PNG SOUND DBUS GSETTINGS GLIB NOTIFY LIBSELINUX GNUTLS
LIBXML2 FREETYPE XFT ZLIB TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES
THREADS LIBSYSTEMD

Important settings:
  value of $LC_MONETARY: de_DE.UTF-8
  value of $LC_NUMERIC: de_DE.UTF-8
  value of $LC_TIME: de_DE.UTF-8
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8

Major mode: Messages

Minor modes in effect:
  pyvenv-mode: t
  helm--remap-mouse-mode: t
  company-quickhelp-mode: t
  company-quickhelp-local-mode: t
  global-company-mode: t
  company-mode: t
  global-git-gutter-mode: t
  global-magit-file-mode: t
  diff-auto-refine-mode: t
  magit-auto-revert-mode: t
  global-git-commit-mode: t
  async-bytecomp-package-mode: t
  shell-dirtrack-mode: t
  which-key-mode: t
  override-global-mode: t
  recentf-mode: t
  savehist-mode: t
  show-paren-mode: t
  global-eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
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/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-contrib hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-contrib
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-headers hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-headers
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-message hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-message
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-icalendar hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-icalendar
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-meta hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-meta
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-main hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-main
/home/mm/.emacs.d/lisp/mu/mu4e/org-mu4e hides 
/usr/local/share/emacs/site-lisp/mu4e/org-mu4e
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-mark hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-mark
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-compose hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-compose
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-org hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-org
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-view hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-view
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-proc hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-proc
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-utils hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-utils
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-lists hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-lists
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-actions hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-actions
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-draft hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-draft
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-context hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-context
/home/mm/.emacs.d/lisp/mu/mu4e/mu4e-speedbar hides 
/usr/local/share/emacs/site-lisp/mu4e/mu4e-speedbar

Features:
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helm-lib projectile grep compile ibuf-ext ibuffer ibuffer-loaddefs
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company-capf company-cmake company-xcode company-clang company-semantic
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gnutls utf7 netrc nnoo parse-time gnus-spec gnus-int gnus-range gnus-win
gnus nnheader mu4e-compose mu4e-context mu4e-draft mu4e-actions
org-capture ido rfc2368 smtpmail sendmail mu4e-mark mu4e-message
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image-mode mu4e-lists hl-line mu4e-vars message rmc puny dired
dired-loaddefs rfc822 mml mml-sec epa derived epg gnus-util rmail
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rfc2045 mm-util ietf-drums mail-prsvr mailabbrev mail-utils gmm-utils
mailheader mu4e-meta use-package use-package-ensure use-package-delight
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byte-opt bytecomp byte-compile cconv gv recentf tree-widget wid-edit
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cl-loaddefs cl-lib time-date mule-util tooltip eldoc electric uniquify
ediff-hook vc-hooks lisp-float-type mwheel term/x-win x-win
term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe
tabulated-list replace newcomment text-mode elisp-mode lisp-mode
prog-mode register page menu-bar rfn-eshadow isearch timer select
scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame cl-generic cham georgian utf-8-lang misc-lang
vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932
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chinese composite charscript charprop case-table epa-hook jka-cmpr-hook
help simple abbrev obarray minibuffer cl-preloaded nadvice loaddefs
button faces cus-face macroexp files text-properties overlay sha1 md5
base64 format env code-pages mule custom widget hashtable-print-readable
backquote threads dbusbind inotify dynamic-setting system-font-setting
font-render-setting move-toolbar gtk x-toolkit x multi-tty
make-network-process emacs)

Memory information:
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