* lisp/mail/rfc2047.el (rfc2047-header-encoding-alist): Encode
Disposition-Notification-To as an address header (bug#54383).
("Followup-To" . nil)
("Message-ID" . nil)
("\\(Resent-\\)?\\(From\\|Cc\\|To\\|Bcc\\|\\(In-\\)?Reply-To\\|Sender\
-\\|Mail-Followup-To\\|Mail-Copies-To\\|Approved\\)" . address-mime)
+\\|Mail-Followup-To\\|Mail-Copies-To\\|Approved\\|Disposition-Notification-To\\)" . address-mime)
(t . mime))
"Header/encoding method alist.
The list is traversed sequentially. The keys can either be