Configuration: Attachment check (Personal website)

Before sending a message, signal an error

if the message mentions attachments but none exist (24).

(with-eval-after-load 'notmuch
  (add-hook 'notmuch-mua-send-hook
            #'notmuch-mua-attachment-check))

“Mentions attachments” as per the notmuch-mua-attachment-regexp.