@introspect Write a function, notmuch-mua-reply-all-check, that checks if I want to reply only to the person I’m responding to, as opposed to using “reply all”. Obviously this check should not complain if the email only involves me and one other person. Use the provided tools to check your assumptions.

Response:

(variable_documentation :variable “notmuch-mua-send-hook”) 
(:name "variable_documentation" :args (:variable "notmuch-mua-send-hook"))

Hook run before sending messages.
(function_documentation :function “notmuch-mua-send-hook”) 
(:name "function_documentation" :args (:function "notmuch-mua-send-hook"))

void-function notmuch-mua-send-hook
(function_completions :function_prefix “notmuch-mua–”) 
(:name "function_completions" :args (:function_prefix "notmuch-mua--"))

notmuch-mua--remove-dont-reply-to-names
(variable_completions :variable_prefix “notmuch-mua-”) 
(:name "variable_completions" :args (:variable_prefix "notmuch-mua-"))

notmuch-mua-send-hook
notmuch-mua-user-agent-function
notmuch-mua-attachment-regexp
notmuch-mua-reply-insert-header-p-function
notmuch-mua-subject-regexp
notmuch-mua-compose-in
notmuch-mua-sender-history
notmuch-mua-hidden-headers
notmuch-mua-cite-function
(function_completions :function_prefix “notmuch-mua-”) 
(:name "function_completions" :args (:function_prefix "notmuch-mua-"))

notmuch-mua-reply-crypto
notmuch-mua-send-and-exit
notmuch-mua-reply
notmuch-mua-maybe-set-window-dedicated
notmuch-mua-subject-check
notmuch-mua-attachment-check
notmuch-mua-send-common
notmuch-mua-check-secure-tag-has-newline
notmuch-mua-mail
notmuch-mua-kill-buffer
notmuch-mua-new-mail
notmuch-mua-pop-to-buffer
notmuch-mua-send
notmuch-mua-check-no-misplaced-secure-tag
notmuch-mua-user-agent-emacs
notmuch-mua-new-forward-messages
notmuch-mua-get-switch-function
notmuch-mua-add-more-hidden-headers
notmuch-mua-insert-references
notmuch-mua-user-agent-full
notmuch-mua-new-reply
notmuch-mua-prompt-for-sender
notmuch-mua-user-agent-notmuch
notmuch-mua--remove-dont-reply-to-names
(variable_completions :variable_prefix “message-”) 
(:name "variable_completions" :args (:variable_prefix "message-"))

gnus-button-message-level
message-signature-setup-hook
clear-message-function
message-yank-cited-prefix
message-smileys
message-inserted-headers
message-subscribed-address-functions
message-archive-note
message-distribution-function
message-options
:message-complete
message-user-organization
message-cross-post-note-function
message-send-mail-function
message-insert-canlock
message-face-alist
message-ignored-supersedes-headers
isearch-original-minibuffer-message-timeout
message-followup-to-function
message-forward-as-mime
message-cross-post-note
message-encoded-mail-cache
my/message-modes-list
minibuffer-message-overlay
message-citation-line-function
message-citation-line-format
tramp-debug-message-fnh-function
message-sendmail-f-is-evil
minibuffer-message-timer
message-mailer
message-mailer-swallows-blank-line
isearch-message-properties
message-posting-charset
magit-revision-wash-message-hook
message-tab-body-function
message-reply-headers
magit-commit-message-section-map
message-return-action
message-field-fillers
:message-id
message-subscribed-addresses
message-yank-prefix
message-cite-style-thunderbird
notmuch-tree-message-window
notmuch-tree-message-buffer
message-send-rename-function
magit-process-error-message-regexps
message-fill-column
dbus-message-type-method-return
message-unique-id-char
gnus-update-message-archive-method
message-forward-included-headers
message-ignored-cited-headers
message-newgroups-header-regexp
message-cite-style
rmail-show-message-hook
message-cross-post-default
sp-message-width
notmuch-message-mode-hook
minibuffer-history-isearch-message-overlay
gnus-action-message-log
nnheader-fake-message-id
message-forward-before-signature
magit-wash-message-hook
notmuch-message-mode-syntax-table
eldoc-message-commands
message-subject-trailing-was-ask-regexp
message-send-mail-hook
message-mode-menu
message-server-alist
message-unix-mail-delimiter
message-openpgp-header
message-postpone-actions
message-user-fqdn
message-newsreader
eldoc-message-commands-table-size
message-followup-to-note
message-deletable-headers
message-cite-level-function
minibuffer-message-timeout
message-header-hook
message-fcc-handler-function
message-send-actions
message-reply-to-function
message-strip-special-text-properties
compilation-message-face
eldoc-message-function
message-log-max
message-dont-reply-to-names
message-send-method-alist
git-commit-use-local-message-ring
message-minibuffer-local-map
isearch-message-prefix-add
message-caesar-translation-table
message-wash-forwarded-subjects
message-wide-reply-to-function
inhibit-message-regexps
message-sent-hook
message-mode-syntax-table
multi-message-timeout
message-cancel-hook
message-bogus-addresses
:message-overlay
message-forward-included-mime-headers
message-qmail-inject-program
x-dnd-motif-message-types
message-header-setup-hook
message-recipients-without-full-name
set-message-function
message-auto-save-directory
message-sending-message
message-header-format-alist
message-ignored-bounced-headers
message-hidden-headers
message-default-news-headers
message-header-synonyms
eat-message-handler-alist
message-send-coding-system
message-cross-post-old-target
message-kill-buffer-on-exit
set-message-functions
message-generate-new-buffers
message-max-buffers
message-form-letter-separator
message-alter-recipients-function
message-cite-style-outlook
message-user-organization-file
message-yank-empty-prefix
message-expand-name-databases
message-email-recipient-header-regexp
ghub-graphql-message-progress
message-indentation-spaces
message-bogus-system-names
message-mime-part
message-cite-prefix-regexp
message-required-headers
message-sendmail-extra-arguments
message-tool-bar-zap-list
message-ignored-news-headers
message-cite-function
notmuch-message-mode-abbrev-table
notmuch-message-forwarded-tags
message-replacement-char
notmuch-message-headers
message-mark-insert-begin
message-fcc-externalize-attachments
comint-history-isearch-message-overlay
multi-message-list
url-lazy-message-time
message-send-mail-real-function
minibuffer-message-clear-timeout
message-screenshot-command
message-post-method
message-signature
message-checksum
message-confirm-send
message-allow-no-recipients
nnmail-message-id-cache-file
message-font-lock-keywords
message-forward-decoded-p
message-use-mail-followup-to
dbus-message-type-error
message-generate-headers-first
message-elide-ellipsis
message-sent-message-via
message-send-news-function
message-cite-articles-with-x-no-archive
message-forward-ignored-headers
message-reply-buffer
notmuch-message-headers-visible
message-cite-reply-position
message-mail-alias-type
message-exit-actions
message-mode-map
message-make-forward-subject-function
message-default-mail-headers
message-directory
message-user-path
message-tool-bar-gnome
message-required-mail-headers
notmuch-message-replied-tags
message-cite-style-gmail
message-signature-file
dbus-message-type-signal
message-hierarchical-addresses
nnmail-prepare-incoming-message-hook
message-sendmail-envelope-from
message-mode-hook
message-subject-trailing-was-query
magit-stash-read-message-function
message--old-style-completion-functions
message-wide-reply-confirm-recipients
message-buffer-list
minibuffer-message-properties
message-send-mail-partially-limit
message-qmail-inject-args
message-draft-coding-system
message-cancel-message
message-subject-trailing-was-regexp
message-courtesy-message
mm-inline-message-prepare-function
cl-struct-compilation--message-tags
message-tool-bar-map
tramp-error-show-message-timeout
message-completion-alist
message-prune-recipient-rules
gnus-message-archive-group
message-this-is-news
message-generate-hashcash
message-truncate-lines
message-send-form-letter-delay
message-use-followup-to
message-send-hook
:message-visible
message-subscribed-regexps
:notmuch-message-extent
nnmail-message-id-cache-length
message-use-idna
next-error--message-highlight-overlay
message-simplify-subject-functions
message-signature-directory
message-default-charset
message-default-headers
rmail-insert-mime-forwarded-message-function
message-kill-buffer-query
message-ignored-mail-headers
message-inhibit-body-encoding
message-required-news-headers
repeat-message-function
message-kill-actions
dbus-message-type-invalid
message-self-insert-commands
log-view-message-re
nnheader-uniquify-message-id
message-alternative-emails
gnus-message-archive-method
dbus-message-type-method-call
message-unsent-separator
message-this-is-mail
message-expires
request-message-level
message-mode-field-menu
multi-message-separator
message-tool-bar-retro
multi-message-max
message-forbidden-properties
message-setup-hook
message-draft-article
nnmail-cache-accepted-message-ids
message-subscribed-address-file
message-subject-re-regexp
message-interactive
message-mh-deletable-headers
message-indent-citation-function
message-forward-show-mml
message-inhibit-ecomplete
message-signature-insert-empty-line
message-signature-separator
nnheader-last-message-time
message-archive-header
message-draft-headers
message-mail-user-agent
message-expand-name-standard-ui
message-syntax-checks
message-mark-insert-end
message-send-news-hook
compilation-exit-message-function
message-extra-wide-headers
next-error-message-highlight
message-beginning-of-line
notmuch-message-queued-tag-changes
isearch-message-suffix-add
:notmuch-message-properties
message-mode-abbrev-table
message-tool-bar
message-from-style
isearch-message-function
notmuch-message-mode-map
message-ignored-resent-headers
sp-message-alist
message-shoot-gnksa-feet
appt-message-warning-time
(function_completions :function_prefix “message-”) 
(:name "function_completions" :args (:function_prefix "message-"))

message-mailto
message-fill-yanked-message
message-setup-fill-variables
message-insert-header
notmuch-show-get-message-ids-for-open-messages
alert-message-notify
message-mail-p
message-goto-mail-followup-to
pop3-get-message-count
eldoc-display-message-p
message-check-element
mml-secure-message-sign-pgpauto
message-text-with-property
message-signed-or-encrypted-p
message-position-point
nnheader-message-maybe
notmuch-show-get-message-id
notmuch-show-stash-message-id
message-send-mail-function
message-sort-headers-1
message-insert-canlock
notmuch-show-message-adjust
message-make-sender
message-send-and-exit
message-idna-to-ascii-rhs-1
message-forward-rmail-make-body
message-sort-headers
message-send-mail-with-qmail
message-mark-insert-file
message-narrow-to-headers-or-head
git-commit-search-message-forward
gnus-message-with-timestamp
message-goto-body
message-canlock-password
message-mail-file-mbox-p
message-fill-field-address
notmuch-tree-show-message-in
message-make-date
eldoc-edit-message-commands
message-wash-subject
message-subscribed-p
org-table-message-once-per-second
message-box
notmuch-show-message-visible
message-news-other-window
notmuch-tree-archive-message-then-next-or-exit
message-news-p
notmuch-tree-message-window-kill-hook
message-next-header
message-insinuate-rmail
message-send-mail-with-mh
message-flatten-list
message-widen-reply
message-insert-disposition-notification-to
imap-list-to-message-set
compilation--message->rule--cmacro
my/notmuch-tree-message-push-button
message-goto-signature
mml-secure-message-encrypt-smime
compilation--message-p--cmacro
message-posting-charset
message-forward-make-body-digest
message-update-smtp-method-header
message-send
message-gnksa-enable-p
message-get-reply-headers
message-completion-function
notmuch-tree-get-message-id
message-use-send-mail-function
notmuch-tree-scroll-message-window
message--cache-encoded
message-check-news-syntax
message-insert-expires
message-fix-before-sending
git-commit-prepare-message-ring
message-is-yours-p
notmuch-show-message-extent
notmuch-show-archive-message-then-next-or-exit
message-cancel-news
mml-secure-message-sign-smime
nnheader-generate-fake-message-id
isearch-message-prefix
message-fill-field
message-remove-ignored-headers
repeat-echo-message-string
notmuch-show-message-top
message-options-get
message-make-expires
message-supersede
message-add-openpgp-header
message-forward-make-body-digest-plain
checkdoc-ispell-message-text
message-buffer-name
isearch-message-suffix
compilation--message->type
message-make-expires-date
compilation--message-p
message-fill-field-general
message-make-caesar-translation-table
message-idna-to-ascii-rhs
message-read-from-minibuffer
message-smtpmail-send-it
notmuch-address-message-insinuate
message-simplify-recipients
message-setup-1
message-generate-unsubscribed-mail-followup-to
notmuch-show-move-to-message-bottom
message-font-lock-make-cited-text-matcher
message-mode-menu
message-rename-buffer
error-message-string
notmuch-show-message-visible-p
message-make-fqdn
gntp-build-message-register
notmuch-show-archive-message-then-next-or-next-thread
message-canlock-generate
message-goto-from
rfc2047-encode-message-header
notmuch-tree-next-message-button
message-fetch-field
message--fold-long-headers
message-forward-make-body-mml
notmuch-tree-previous-message-button
message-insert-newsgroups
message-make-mail-followup-to
message-shorten-1
message-mail-other-window
message-make-organization
message-caesar-buffer-body
message-do-send-housekeeping
message-dont-reply-to-names
message-bounce
alert-message-remove
compilation--message->end-loc--cmacro
message-insert-wide-reply
message-send-form-letter
message-newline-and-reformat
message-widen-and-recenter
message-default-send-rename-function
message-insert-citation-line
message-forward-subject-name-subject
message-parse-mailto-url
message-remove-header
gnus-mime--inline-message-function
message-mailto-1
message-reduce-to-to-cc
message--send-mail-maybe-partially
message-options-set-recipient
message-clone-locals
message-add-header
mml-secure-message-sign
message-strip-subject-re
message-pop-to-buffer
compilation--message->end-loc
message-insert-importance-low
notmuch-tree-outline--message-open-p
compilation--message->loc--cmacro
message-headers-to-generate
message-position-on-field
notmuch-show-set-message-properties
message-check-recipients
server--message-sit-for
message-check-news-header-syntax
message-tamago-not-in-use-p
message--yank-original-internal
message-all-epg-keys-available-p
message-fill-paragraph
nnheader-fake-message-id-p
message--alter-repeat-address
log-edit-insert-message-template
notmuch-tree-set-message-properties
set-message-functions
message-expand-name
message-do-actions
message-split-line
message-hide-header-p
message-wide-reply
message-insert-or-toggle-importance
message-expand-group
message-bold-region
message-goto-distribution
mml-secure-message-encrypt-pgpmime
message-carefully-insert-headers
org-mhe-get-message-real-folder
my/notmuch-tree-show-message-split-sensibly
message-bury
message-narrow-to-field
message-goto-followup-to
dbus-event-message-type
message-use-alternative-email-as-from
vc-message-unresolved-conflicts
message-kill-address
message-insert-to
message-cross-post-insert-note
eudc-capf-message-expand-name
message-delete-line
message-add-archive-header
minibuffer--message-overlay-pos
git-commit-search-message-backward
message-generate-new-buffer-clone-locals
message-yank-buffer
dbus-message-internal
message-beginning-of-header
message-make-tool-bar
notmuch-tree-scroll-message-window-back
message-display-abbrev
message-narrow-to-head-1
notmuch-message-mode
message-add-action
message-bogus-recipient-p
notmuch-tree-show-message-out
message-make-domain
notmuch-show-goto-message-previous
message-cite-original-without-signature
message-checksum
checkdoc-ispell-message-interactive
message-strip-forbidden-properties
gnus--abort-on-unsaved-message-buffers
notmuch-show-get-message-properties
message-alter-recipients-discard-bogus-full-name
message-do-fcc
message-unique-id
isearch--state-message--cmacro
message-mark-active-p
magit-stash-read-message-traditional
notmuch-tree--message-process-crypto
notmuch-tree-get-message-properties
notmuch-maildir-message-do-fcc
message-recover
message-send-via-mail
mml-secure-message-sign-pgpmime
message-narrow-to-headers
message-disassociate-draft
message--yank-media-image-handler
message-send-via-news
message-cite-original-1
message-talkative-question
message-sign-encrypt-if-all-keys-available
message--default-send-mail-function
message-cross-post-followup-to-header
message-prune-recipients
imap-message-flags-add
message-insert-importance-high
imap-range-to-message-set
compilation--message->loc
message-make-references
message-news
message-send-mail-partially
message-indent-citation
message-all-recipients
message-field-name
gnus-select-group-with-message-id
message-reply
message-remove-blank-cited-lines
mml-secure-message-encrypt-pgpauto
message-forward-make-body-plain
message--image-part-string
message-goto-body-1
message-do-auto-fill
select-message-coding-system
message-goto-to
message-news-other-frame
message-remove-first-header
message-goto-newsgroups
message-point-in-header-p
gnus-button-message-id
mml-secure-message-encrypt
org-mhe-get-message-folder-from-index
message-narrow-to-head
message-sendmail-envelope-from
message-number-base36
message-mode
message-send-mail
message-make-message-id
message-insert-signature
message-goto-summary
message-kill-to-signature
message-hide-headers
org-mhe-get-message-num
message-setup
message-goto-cc
notmuch-tree-close-message-window
message-mark-inserted-region
message-make-forward-subject
notmuch-show-with-message-as-text
message-match-to-eoh
message-pipe-buffer-body
message-fetch-reply-field
message-in-body-p
message-make-html-message-with-image-files
message-followup
message-buffers
message-skip-to-next-address
popper-message-shorten
message-or-box
message-make-distribution
message-make-in-reply-to
message-yank-original
message-insert-courtesy-copy
plz-error-message--cmacro
message-insert-formatted-citation-line
message--sendmail-envelope-from
message-toggle-image-thumbnails
message-ecomplete-capf
notmuch-maildir-setup-message-for-saving
message-tokenize-header
message-user-mail-address
message-delete-action
eldoc-display-message-no-interference-p
mml-secure-message-sign-encrypt
message-to-list-only
checkdoc-message-text
message-shorten-references
nnimap-find-article-by-message-id
message-dont-send
message-send-news
message-goto-reply-to
gnutls-message-maybe
message-multi-smtp-send-mail
deferred:message-mark
notmuch-show-stash-message-id-stripped
message-forward-subject-fwd
message-mail-other-frame
message-goto-keywords
message-field-value
gnus-extract-message-id-from-in-reply-to
message--in-tocc-p
org-mhe-get-message-folder
message-cite-original
message-delete-not-region
message-forward-subject-author-subject
message-set-auto-save-file-name
nnmail-message-id
checkdoc-message-interactive
gnus-summary-line-message-size
message-simplify-subject
notmuch-message-apply-queued-tag-changes
message-change-subject
tramp-debug-message-buttonize
message-cleanup-headers
message-kill-buffer
notmuch-show-message-bottom
message-default-send-mail-function
notmuch-tree-archive-message-then-next
message-encode-message-body
message-options-set
message--check-continuation-headers
message-make-from
notmuch-draft--make-message-id
compilation--message->rule
message-goto-fcc
message-goto-bcc
message-elide-region
message-output
message-mode-field-menu
message-mail-alias-type-p
message-unbold-region
message--match-signature
message--bbdb-query-with-words
message-send-mail-with-sendmail
message-goto-subject
message-make-path
message--update-image-crop
message-check-news-body-syntax
message--rotate-fixnum-left
notmuch-tree-toggle-message-process-crypto
message-forward-make-body-mime
display-message-or-buffer
message-exchange-point-and-mark
message-strip-subject-encoded-words
message-strip-subject-trailing-was
mml-secure-message-encrypt-pgp
compilation--make-message--cmacro
message-replace-header
message-strip-list-identifiers
message-caesar-region
message-kill-all-overlays
xref-bogus-location-message--cmacro
message-send-mail-with-mailclient
eldoc--message-command-p
message--name-table
message-mail-user-agent
message-insert-screenshot
message-setup-toolbar
message-forward-make-body-digest-mime
mail-header-message-id
message-put-addresses-in-ecomplete
fennel-proto-repl-send-message-sync
message-insert-headers
message-resend
message-forward-make-body
next-error-message-highlight
message-make-lines
notmuch-message--fold-long-headers
message-beginning-of-line
message-generate-headers
message-cross-post-followup-to
message-mail
message-forward
message-goto-eoh
mml-secure-message-sign-pgp
magit-commit-message-buffer
gntp-build-message-notify
compilation--message->type--cmacro
notmuch-show-goto-message-next
message-make-address
message-info
message-tab
notmuch-show-move-to-message-top
magit-revision--wash-message-hashes
message--syntax-propertize
message-unquote-tokens
(variable_value :variable “message-reply-to”) 
(:name "variable_value" :args (:variable "message-reply-to"))

nil
(variable_value :variable “message-reply-to”) 
(:name "variable_value" :args (:variable "message-reply-to"))

nil
(function_documentation :function “message-goto-to”) 
(:name "function_documentation" :args (:function "message-goto-to"))

Move point to the To header or insert an empty one.
(function_documentation :function “message-goto-cc”) 
(:name "function_documentation" :args (:function "message-goto-cc"))

Move point to the Cc header or insert an empty one.
(function_documentation :function "message-remove-ign …) 
(:name "function_documentation" :args (:function "message-remove-ignored-headers"))



(fn B E &optional PRESERVE-MIME)
(function_documentation :function "message-mail-user- …) 
(:name "function_documentation" :args (:function "message-mail-user-agent"))

nil
(function_documentation :function "message-remove-ign …) 
(:name "function_documentation" :args (:function "message-remove-ignored-headers"))



(fn B E &optional PRESERVE-MIME)
(function_documentation :function “message-field-value”) 
(:name "function_documentation" :args (:function "message-field-value"))

The same as ‘message-fetch-field’, only narrow to the headers first.

(fn HEADER &optional FIRST)
(function_documentation :function “message-fetch-field”) 
(:name "function_documentation" :args (:function "message-fetch-field"))

Return the value of the header field named HEADER.
Continuation lines are folded (i.e., newlines are removed).
Surrounding whitespace is also removed.

By default, if there’s more than one header field named HEADER,
all the values are returned as one concatenated string, and
values are comma-separated.

If FIRST is non-nil, only the first value is returned.

The buffer is expected to be narrowed to just the header of the message;
see ‘message-narrow-to-headers-or-head’.

(fn HEADER &optional FIRST)
(function_documentation :function "mail-extract-addre …) 
(:name "function_documentation" :args (:function "mail-extract-address-components"))

Extract full name and canonical address from ADDRESS.
ADDRESS should be in RFC 822 (or later) format.
Returns a list of the form (FULL-NAME CANONICAL-ADDRESS).  If no
name can be extracted, FULL-NAME will be nil.  Also see
‘mail-extr-ignore-single-names’ and
‘mail-extr-ignore-realname-equals-mailbox-name’.

If the optional argument ALL is non-nil, then ADDRESS can contain zero
or more recipients, separated by commas, and we return a list of
the form ((FULL-NAME CANONICAL-ADDRESS) ...) with one element for
each recipient.  If ALL is nil, then if ADDRESS contains more than
one recipients, all but the first is ignored.

ADDRESS may be a string or a buffer.  If it is a buffer, the visible
(narrowed) portion of the buffer will be interpreted as the address.
(This feature exists so that the clever caller might be able to avoid
consing a string.)

This function is primarily meant for when you’re displaying the
result to the user: Many prettifications are applied to the
result returned.  If you want to decode an address for further
non-display use, you should probably use
‘mail-header-parse-address’ instead.  Also see
‘mail-header-parse-address-lax’ for a function that’s less strict
than ‘mail-header-parse-address’, but does less post-processing
to the results.

(fn ADDRESS &optional ALL)
(function_documentation :function "mail-header-parse- …) 
(:name "function_documentation" :args (:function "mail-header-parse-address"))

Parse STRING and return a MAILBOX / DISPLAY-NAME pair.
STRING here is supposed to be an RFC822(bis) mail address, and
will commonly look like, for instance:

"=?utf-8?Q?Andr=C3=A9?= <andre@example.com>"

If you have an already-decoded address, like

"André <andre@example.com>"

this function can’t be used to parse that.  Instead, use
‘mail-header-parse-address-lax’ to make a guess at what’s the
name and what’s the address.

If DECODE, the DISPLAY-NAME will have RFC2047 decoding performed
(that’s the "=?utf...q...=?") stuff.

(fn STRING &optional DECODE)
(function_documentation :function "mail-header-parse- …) 
(:name "function_documentation" :args (:function "mail-header-parse-address-lax"))

Parse STRING as a mail address.
Returns a mail/name pair.

This function uses heuristics to determine the email address and
the name in the string.  If you have an RFC822(bis)
standards-compliant STRING, use ‘mail-header-parse-address’
instead.

(fn STRING)
(function_documentation :function “message-to-list”) 
(:name "function_documentation" :args (:function "message-to-list"))

nil
(function_documentation :function "mail-header-parse- …) 
(:name "function_documentation" :args (:function "mail-header-parse-addr"))

nil
(function_documentation :function "message-simplify-r …) 
(:name "function_documentation" :args (:function "message-simplify-recipients"))

nil
(function_documentation :function "message-all-recipi …) 
(:name "function_documentation" :args (:function "message-all-recipients"))

Return a list of all recipients in the message, looking at TO, Cc and Bcc.

Each recipient is in the format of ‘mail-extract-address-components’.
(function_documentation :function "mail-extract-addre …) 
(:name "function_documentation" :args (:function "mail-extract-address-components"))

Extract full name and canonical address from ADDRESS.
ADDRESS should be in RFC 822 (or later) format.
Returns a list of the form (FULL-NAME CANONICAL-ADDRESS).  If no
name can be extracted, FULL-NAME will be nil.  Also see
‘mail-extr-ignore-single-names’ and
‘mail-extr-ignore-realname-equals-mailbox-name’.

If the optional argument ALL is non-nil, then ADDRESS can contain zero
or more recipients, separated by commas, and we return a list of
the form ((FULL-NAME CANONICAL-ADDRESS) ...) with one element for
each recipient.  If ALL is nil, then if ADDRESS contains more than
one recipients, all but the first is ignored.

ADDRESS may be a string or a buffer.  If it is a buffer, the visible
(narrowed) portion of the buffer will be interpreted as the address.
(This feature exists so that the clever caller might be able to avoid
consing a string.)

This function is primarily meant for when you’re displaying the
result to the user: Many prettifications are applied to the
result returned.  If you want to decode an address for further
non-display use, you should probably use
‘mail-header-parse-address’ instead.  Also see
‘mail-header-parse-address-lax’ for a function that’s less strict
than ‘mail-header-parse-address’, but does less post-processing
to the results.

(fn ADDRESS &optional ALL)
(function_documentation :function “message-fetch-field”) 
(:name "function_documentation" :args (:function "message-fetch-field"))

Return the value of the header field named HEADER.
Continuation lines are folded (i.e., newlines are removed).
Surrounding whitespace is also removed.

By default, if there’s more than one header field named HEADER,
all the values are returned as one concatenated string, and
values are comma-separated.

If FIRST is non-nil, only the first value is returned.

The buffer is expected to be narrowed to just the header of the message;
see ‘message-narrow-to-headers-or-head’.

(fn HEADER &optional FIRST)

Plan for notmuch-mua-reply-all-check function:

  1. Retrieve the list of all recipients (To, Cc, Bcc) using message-all-recipients.
  2. Extract the canonical email addresses from these recipients using mail-extract-address-components.
  3. Get the “From” or the main replying address (using message-fetch-field with “From”).
  4. If the total number of distinct recipients is <= 2 (including the sender), do nothing — no complaint.
  5. If there are more than 2 recipients, ask with y-or-n-p if the user intends to reply only to the sender rather than all.
  6. If the user says no, signal an error to prevent sending.

I’ll check that message-all-recipients and mail-extract-address-components exist and their calling conventions before proceeding.

(function_documentation :function "message-all-recipi …) 
(:name "function_documentation" :args (:function "message-all-recipients"))

Return a list of all recipients in the message, looking at TO, Cc and Bcc.

Each recipient is in the format of ‘mail-extract-address-components’.
(function_documentation :function "mail-extract-addre …) 
(:name "function_documentation" :args (:function "mail-extract-address-components"))

Extract full name and canonical address from ADDRESS.
ADDRESS should be in RFC 822 (or later) format.
Returns a list of the form (FULL-NAME CANONICAL-ADDRESS).  If no
name can be extracted, FULL-NAME will be nil.  Also see
‘mail-extr-ignore-single-names’ and
‘mail-extr-ignore-realname-equals-mailbox-name’.

If the optional argument ALL is non-nil, then ADDRESS can contain zero
or more recipients, separated by commas, and we return a list of
the form ((FULL-NAME CANONICAL-ADDRESS) ...) with one element for
each recipient.  If ALL is nil, then if ADDRESS contains more than
one recipients, all but the first is ignored.

ADDRESS may be a string or a buffer.  If it is a buffer, the visible
(narrowed) portion of the buffer will be interpreted as the address.
(This feature exists so that the clever caller might be able to avoid
consing a string.)

This function is primarily meant for when you’re displaying the
result to the user: Many prettifications are applied to the
result returned.  If you want to decode an address for further
non-display use, you should probably use
‘mail-header-parse-address’ instead.  Also see
‘mail-header-parse-address-lax’ for a function that’s less strict
than ‘mail-header-parse-address’, but does less post-processing
to the results.

(fn ADDRESS &optional ALL)
(function_documentation :function “message-fetch-field”) 
(:name "function_documentation" :args (:function "message-fetch-field"))

Return the value of the header field named HEADER.
Continuation lines are folded (i.e., newlines are removed).
Surrounding whitespace is also removed.

By default, if there’s more than one header field named HEADER,
all the values are returned as one concatenated string, and
values are comma-separated.

If FIRST is non-nil, only the first value is returned.

The buffer is expected to be narrowed to just the header of the message;
see ‘message-narrow-to-headers-or-head’.

(fn HEADER &optional FIRST)

Plan for notmuch-mua-reply-all-check:

  1. Fetch all recipients from the message headers including “To”, “Cc”, “Bcc” using message-all-recipients.
  2. Parse the “From” header to get the main person being replied to.
  3. If there are only two addresses total (including your own), do not complain.
  4. If more than two addresses, ask user if reply all is intended.
  5. If user rejects, signal an error to prevent sending.

I will now implement this.

(function_source :function “notmuch-mua-reply-all-check”) 
(:name "function_source" :args (:function "notmuch-mua-reply-all-check"))

nil

Plan:

  1. Use message-all-recipients to get all recipients in To, Cc, Bcc.
  2. Parse the sender address from the message header “From” using message-fetch-field and mail-extract-address-components.
  3. Count unique recipients ignoring the sender’s address.
  4. If only one other recipient besides the sender, do nothing (return nil).
  5. Otherwise prompt the user if they want to only reply to the original sender (not reply all).
  6. If user says no, signal an error.

I will create the function notmuch-mua-reply-all-check accordingly. I will check the existence and arity of the functions I plan to use before coding.

(symbol_exists :symbol “message-all-recipients”) 
(:name "symbol_exists" :args (:symbol "message-all-recipients"))

message-all-recipients
(symbol_exists :symbol “message-fetch-field”) 
(:name "symbol_exists" :args (:symbol "message-fetch-field"))

message-fetch-field
(symbol_exists :symbol “mail-extract-address-components”) 
(:name "symbol_exists" :args (:symbol "mail-extract-address-components"))

mail-extract-address-components
(function_documentation :function "message-all-recipi …) 
(:name "function_documentation" :args (:function "message-all-recipients"))

Return a list of all recipients in the message, looking at TO, Cc and Bcc.

Each recipient is in the format of ‘mail-extract-address-components’.
(function_documentation :function “message-fetch-field”) 
(:name "function_documentation" :args (:function "message-fetch-field"))

Return the value of the header field named HEADER.
Continuation lines are folded (i.e., newlines are removed).
Surrounding whitespace is also removed.

By default, if there’s more than one header field named HEADER,
all the values are returned as one concatenated string, and
values are comma-separated.

If FIRST is non-nil, only the first value is returned.

The buffer is expected to be narrowed to just the header of the message;
see ‘message-narrow-to-headers-or-head’.

(fn HEADER &optional FIRST)
(function_documentation :function "mail-extract-addre …) 
(:name "function_documentation" :args (:function "mail-extract-address-components"))

Extract full name and canonical address from ADDRESS.
ADDRESS should be in RFC 822 (or later) format.
Returns a list of the form (FULL-NAME CANONICAL-ADDRESS).  If no
name can be extracted, FULL-NAME will be nil.  Also see
‘mail-extr-ignore-single-names’ and
‘mail-extr-ignore-realname-equals-mailbox-name’.

If the optional argument ALL is non-nil, then ADDRESS can contain zero
or more recipients, separated by commas, and we return a list of
the form ((FULL-NAME CANONICAL-ADDRESS) ...) with one element for
each recipient.  If ALL is nil, then if ADDRESS contains more than
one recipients, all but the first is ignored.

ADDRESS may be a string or a buffer.  If it is a buffer, the visible
(narrowed) portion of the buffer will be interpreted as the address.
(This feature exists so that the clever caller might be able to avoid
consing a string.)

This function is primarily meant for when you’re displaying the
result to the user: Many prettifications are applied to the
result returned.  If you want to decode an address for further
non-display use, you should probably use
‘mail-header-parse-address’ instead.  Also see
‘mail-header-parse-address-lax’ for a function that’s less strict
than ‘mail-header-parse-address’, but does less post-processing
to the results.

(fn ADDRESS &optional ALL)
(elisp_eval :expression “(notmuch-mua-reply-all-check)”) 
(:name "elisp_eval" :args (:expression "(notmuch-mua-reply-all-check)"))

void-function notmuch-mua-reply-all-check

Plan to implement notmuch-mua-reply-all-check:

  1. Get the list of all recipients from the message headers (To, Cc, Bcc) via message-all-recipients.
  2. Extract the canonical addresses from those recipients using mail-extract-address-components.
  3. Extract the canonical address of the “to” header recipient (the person replied to).
  4. If the number of unique recipients is <= 1 (only me and possibly one other) then no complaint.
  5. Otherwise, check if the user intends to reply only to one person (the “to” recipient).
  6. If yes, prompt the user if they want to restrict reply only to the “to” recipient, else no error.
  7. If the user refuses, signal an error.

Now, I will implement the function.

(symbol_exists :symbol “notmuch-mua-reply-all-check”) 
(:name "symbol_exists" :args (:symbol "notmuch-mua-reply-all-check"))

notmuch-mua-reply-all-check

Plan:

  1. Get all recipients in To, Cc, Bcc headers using message-all-recipients.
  2. Extract only the email addresses (canonical) from these recipients.
  3. Get the reply-to address from the header Reply-To or from From as a fallback.
  4. Compare the recipients list ignoring the reply-to address.
  5. If there are other recipients besides the reply-to and self, prompt the user if they want to reply only to the individual (not “Reply All”).
  6. If the user doesn’t want to reply only to the individual, signal an error to warn about accidental “Reply All”.

I will write the function now.

(elisp_eval :expression "(defun notmuch-mua-reply-all …) 
(:name "elisp_eval" :args (:expression "(defun notmuch-mua-reply-all-check ()
  \"Check if user wants to reply only to the person they're responding to, not 'reply all'.
If there is only one other person (and self) no message is shown.
Prompts the user if there are multiple recipients including self and others.
Signals an error if user rejects replying only to the original sender.\"
  (let* ((recipients (mapcar #'cadr (message-all-recipients)))
         (reply-to (or (message-fetch-field \"Reply-To\" t) (message-fetch-field \"From\" t)))
         (self (car (mail-extract-address-components (mail-host-address))))
         (reply-to-address (cadr (mail-extract-address-components reply-to)))
         (filtered (seq-remove (lambda (addr) (or (string= addr reply-to-address)
                                                 (string= addr self))) recipients))
         (multiple-others (> (length filtered) 0)))
    (when multiple-others
      (unless (y-or-n-p \"This message has other recipients besides the one you're replying to. Reply only to the original sender? \")
        (error \"Aborting send to avoid unintentional Reply-All\")))))"))

notmuch-mua-reply-all-check

I have written notmuch-mua-reply-all-check:

Code: 

(defun notmuch-mua-reply-all-check ()
  "Check if user wants to reply only to the person they're responding to, not 'reply all'.
If there is only one other person (and self) no message is shown.
Prompts the user if there are multiple recipients including self and others.
Signals an error if user rejects replying only to the original sender."
  (let* ((recipients (mapcar #'cadr (message-all-recipients)))
         (reply-to (or (message-fetch-field "Reply-To" t) (message-fetch-field "From" t)))
         (self (car (mail-extract-address-components (mail-host-address))))
         (reply-to-address (cadr (mail-extract-address-components reply-to)))
         (filtered (seq-remove (lambda (addr) (or (string= addr reply-to-address)
                                                 (string= addr self))) recipients))
         (multiple-others (> (length filtered) 0)))
    (when multiple-others
      (unless (y-or-n-p "This message has other recipients besides the one you're replying to. Reply only to the original sender? ")
        (error "Aborting send to avoid unintentional Reply-All")))))

Prompt: Thanks

Author: Karthik Chikmagalur

Created: 2025-08-06 Wed 13:35

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