ARC: give more detail with "bad signing-spec" message

[exim.git] / doc / doc-txt / experimental-spec.txt

diff --git a/doc/doc-txt/experimental-spec.txt b/doc/doc-txt/experimental-spec.txt
index 149598ee8934b5465983a5271cd9634a65688bb6..2ed6e358208a5f0790e39186dfcefd293b1a481f 100644 (file)
--- a/doc/doc-txt/experimental-spec.txt
+++ b/doc/doc-txt/experimental-spec.txt
@@ -799,7 +799,8 @@ arc_sign = <admd-identifier> : <selector> : <privkey>
 An option on the smtp transport, which constructs and prepends to the message
 an ARC set of headers.  The textually-first Authentication-Results: header
 is used as a basis (you must have added one on entry to the ADMD).
-Expanded; if unset, empty or forced-failure then no signing is done.
+Expanded as a whole; if unset, empty or forced-failure then no signing is done.
+If it is set, all three elements must be non-empty.