/div>
    <p></p>
    Emacs’s <code>notmuch</code> package has this fantastic concept of an <em>attachment check</em>:
adding <code>notmuch-mua-attachment-check</code> to <code>notmuch-mua-send-hook</code> will,
before sending the message,
check whether the regular expression in <code>notmuch-mua-attachment-regexp</code> matches.
If yes—and no attachment has been added—it will alert the user,
asking whether one really wants to send that email;
otherwise, everything goes through smoothly.
Due to some p