+ ;; Do not invoke this from nntp-server-buffer! At least nnfolder clears
+ ;; that buffer if the nnfolder group isn't selected.
+ (let (nnmail-cache-accepted-message-ids)
+ ;; Don't enter Message-IDs into cache.
+ ;; Let users hack it in TARGET function.
+ (when (nnheader-functionp target)
+ (setq target (funcall target group)))
+ (unless (eq target 'delete)
+ (when (or (gnus-request-group target)
+ (gnus-request-create-group target))
+ (let ((group-art (gnus-request-accept-article target nil nil t)))
+ (when (consp group-art)
+ (gnus-group-mark-article-read target (cdr group-art))))))))
+
+(defun nnmail-fancy-expiry-target (group)
+ "Returns a target expiry group determined by `nnmail-fancy-expiry-targets'."
+ (let* (header
+ (case-fold-search nil)
+ (from (or (message-fetch-field "from") ""))
+ (to (or (message-fetch-field "to") ""))
+ (date (date-to-time
+ (or (message-fetch-field "date") (current-time-string))))
+ (target 'delete))
+ (dolist (regexp-target-pair (reverse nnmail-fancy-expiry-targets) target)
+ (setq header (car regexp-target-pair))
+ (cond
+ ;; If the header is to-from then match against the
+ ;; To or From header
+ ((and (equal header 'to-from)
+ (or (string-match (cadr regexp-target-pair) from)
+ (and (string-match message-dont-reply-to-names from)
+ (string-match (cadr regexp-target-pair) to))))
+ (setq target (format-time-string (caddr regexp-target-pair) date)))
+ ((and (not (equal header 'to-from))
+ (string-match (cadr regexp-target-pair)
+ (or
+ (message-fetch-field header)
+ "")))
+ (setq target
+ (format-time-string (caddr regexp-target-pair) date)))))))