Add more headers to default value of rmail-retry-ignored-headers.

* rmail.el (rmail-retry-ignored-headers): Add more headers to default.
Don't bother with `purecopy'.  Split value readably.

diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index fed0a2057bc29c11eb4284a8a3b87de4f333d666..9cc097d28dda3241de73bf7becb7f5d4401ad35c 100644 (file)
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -372,11 +372,17 @@ If nil, display all header fields except those matched by
   :group 'rmail-headers)
 
 ;;;###autoload
-(defcustom rmail-retry-ignored-headers (purecopy "^x-authentication-warning:\\|^x-detected-operating-system:\\|^x-spam[-a-z]*:\\|content-type:\\|content-transfer-encoding:\\|mime-version:\\|message-id:")
+(defcustom rmail-retry-ignored-headers
+  (concat "^x-authentication-warning:\\|^x-detected-operating-system:\\|"
+          "^x-spam[-a-z]*:\\|^arc-.*:\\|"
+          "^content-type:\\|^content-transfer-encoding:\\|"
+          "^mime-version:\\|^message-id:\\|^x-google-smtp-source:\\|"
+          "^x-received:\\|^received-spf:\\|"
+          "^authentication-results:\\|^dkim-signature:")
   "Headers that should be stripped when retrying a failed message."
   :type '(choice regexp (const :value nil :tag "None"))
   :group 'rmail-headers
-  :version "23.2")        ; added x-detected-operating-system, x-spam
+  :version "23.2")
 
 ;;;###autoload
 (defcustom rmail-highlighted-headers (purecopy "^From:\\|^Subject:")