Content scanning: Fix locking on message spool files. Bug 2275

[users/heiko/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 d51169073cc73b1746917ba7a3909b356567414e..15df152676844c9dcd5dece3ea648ec2edd7a997 100644 (file)
--- a/doc/doc-txt/experimental-spec.txt
+++ b/doc/doc-txt/experimental-spec.txt
@@ -793,7 +793,21 @@ standard header.
        Note that it would be wise to strip incoming messages of A-R headers
        that claim to be from our own <admd-identifier>.
 
-There are two new variables: $arc_state and $arc_state_reason.
+There are three new variables: $arc_state, $arc_state_reason, $arc_domains:
+
+  $arc_state           One of pass, fail, none
+  $arc_state_reason    (if fail, why)
+  $arc_domains         colon-sep list of ARC chain domains, in chain order.
+                       problematic elements may have empty list elements
+  $arc_oldest_pass     lowest passing instance number of chain
+
+Example:
+  logwrite = oldest-p-ams: <${reduce {$lh_ARC-Authentication-Results:} \
+                               {} \
+                               {${if = {$arc_oldest_pass} \
+                                       {${extract {i}{${extract {1}{;}{$item}}}}} \
+                                       {$item} {$value}}} \
+                           }>
 
 Receive log lines for an ARC pass will be tagged "ARC".
 
@@ -808,9 +822,15 @@ 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.
 
 The fourth element is optional, and if present consists of a comma-separated list
-of options.  The only option implemented so far is
-  timestamps    Add a t= tag to the generated AMS and AS headers, with the
-                current time.
+of options.  The options implemented are
+
+  timestamps           Add a t= tag to the generated AMS and AS headers, with the
+                       current time.
+  expire[=<val>]       Add an x= tag to the generated AMS header, with an expiry time.
+                       If the value <val> is an plain number it is used unchanged.
+                       If it starts with a '+' then the following number is added
+                       to the current time, as an offset in seconds.
+                       If a value is not given it defaults to a one month offset.
 
 [As of writing, gmail insist that a t= tag on the AS is mandatory]