Doc: add clarification for DKIM example

[exim.git] / doc / doc-docbook / spec.xfpt

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 622e5272d31f0e38e1f1333c3ff6e452ecd77fd7..54775aecd01c1bffb586bcb42168ba6810f47e5d 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -6268,7 +6268,11 @@ Chapter &<<CHAPplaintext>>& covers both.
 Exim supports the use of regular expressions in many of its options. It
 uses the PCRE regular expression library; this provides regular expression
 matching that is compatible with Perl 5. The syntax and semantics of
-regular expressions is discussed in many Perl reference books, and also in
+regular expressions is discussed in
+.new
+online Perl manpages, in
+.wen
+many Perl reference books, and also in
 Jeffrey Friedl's &'Mastering Regular Expressions'&, which is published by
 O'Reilly (see &url(http://www.oreilly.com/catalog/regex2/)).
 
@@ -13003,8 +13007,7 @@ or external command, as described above. It is also used during a
 
 .vitem &$verify_mode$&
 .vindex "&$verify_mode$&"
-While a router or transport is being run in verify mode
-or for cutthrough delivery,
+While a router or transport is being run in verify mode or for cutthrough delivery,
 contains "S" for sender-verification or "R" for recipient-verification.
 Otherwise, empty.
 
@@ -28802,7 +28805,7 @@ Notice that we put back the lower cased version afterwards, assuming that
 is what is wanted for subsequent tests.
 
 
-.vitem &*control&~=&~cutthrough_delivery*&
+.vitem &*control&~=&~cutthrough_delivery/*&<&'options'&>
 .cindex "&ACL;" "cutthrough routing"
 .cindex "cutthrough" "requesting"
 This option requests delivery be attempted while the item is being received.
@@ -28842,11 +28845,20 @@ It is not supported for messages received with the SMTP PRDR option in use.
 
 Should the ultimate destination system positively accept or reject the mail,
 a corresponding indication is given to the source system and nothing is queued.
-If there is a temporary error the item is queued for later delivery in the
-usual fashion. If the item is successfully delivered in cutthrough mode
+If the item is successfully delivered in cutthrough mode
 the delivery log lines are tagged with ">>" rather than "=>" and appear
 before the acceptance "<=" line.
 
+.new
+If there is a temporary error the item is queued for later delivery in the
+usual fashion.
+This behaviour can be adjusted by appending the option &*defer=*&<&'value'&>
+to the control; the default value is &"spool"& and the alternate value
+&"pass"& copies an SMTP defer response from the target back to the initiator
+and does not queue the message.
+Note that this is independent of any receipient verify conditions in the ACL.
+.wen
+
 Delivery in this mode avoids the generation of a bounce mail to a
 (possibly faked)
 sender when the destination system is doing content-scan based rejection.
@@ -38367,13 +38379,18 @@ for a match against the domain or identity that the ACL is currently verifying
 verb to a group of domains or identities. For example:
 
 .code
-# Warn when Mail purportedly from GMail has no signature at all
-warn log_message = GMail sender without DKIM signature
+# Warn when Mail purportedly from GMail has no gmail signature
+warn log_message = GMail sender without gmail.com DKIM signature
      sender_domains = gmail.com
      dkim_signers = gmail.com
      dkim_status = none
 .endd
 
+.new
+Note that the above does not check for a total lack of DKIM signing;
+for that check for empty &$h_DKIM-Signature:$& in the data ACL.
+.wen
+
 .vitem &%dkim_status%&
 ACL condition that checks a colon-separated list of possible DKIM verification
 results against the actual result of verification. This is typically used