Basic documentation for cutthrough.

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 0ea36adc24fe15a3ff3727a026cd3ff1d0085b8e..02aff0662ea0798ea31c5858dd4b9a45e412b373 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -26905,6 +26905,27 @@ Notice that we put back the lower cased version afterwards, assuming that
 is what is wanted for subsequent tests.
 
 
 is what is wanted for subsequent tests.
 
 

+.new
+.vitem &*control&~=&~cutthrough_delivery*&
+.cindex "&ACL;" "cutthrough routing"
+This option requests delivery be attempted while the item is being received.
+It is usable in the RCPT ACL and valid only for single-recipient mails forwarded
+from one SMTP connection to another.  If a recipient-verify callout connection is
+requested in the same ACL it is held open and used for the data, otherwise one is made
+after the ACL completes.
+
+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 the log line
+is tagged with ">>" rather than "=>" and appears before the acceptance "<="
+line.
+
+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.
+.wen
+
+

 .new
 .vitem &*control&~=&~dscp/*&<&'value'&>
 .cindex "&ACL;" "setting DSCP value"
 .new
 .vitem &*control&~=&~dscp/*&<&'value'&>
 .cindex "&ACL;" "setting DSCP value"


@@ -31632,6 +31653,8 @@ required for the transaction.
 If the remote server advertises support for the STARTTLS command, and Exim
 was built to support TLS encryption, it tries to start a TLS session unless the
 server matches &%hosts_avoid_tls%&. See chapter &<<CHAPTLS>>& for more details.
 If the remote server advertises support for the STARTTLS command, and Exim
 was built to support TLS encryption, it tries to start a TLS session unless the
 server matches &%hosts_avoid_tls%&. See chapter &<<CHAPTLS>>& for more details.

+Either a match in that or &%hosts_verify_avoid_tls%& apply when the transport
+is called for verification.

 
 If the remote server advertises support for the AUTH command, Exim scans
 the authenticators configuration for any suitable client settings, as described
 
 If the remote server advertises support for the AUTH command, Exim scans
 the authenticators configuration for any suitable client settings, as described

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index ecf3985a61a07fea927caecc3004e012599919b6..02f526756498f7a465b36d5b589a348ea9a5280e 100644 (file)
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -33,6 +33,8 @@ PP/07 Handle "exim -L <tag>" to indicate to use syslog with tag as the process
 
 TL/01 Bugzilla 1258 - Refactor MAIL FROM optional args processing.
 
 
 TL/01 Bugzilla 1258 - Refactor MAIL FROM optional args processing.
 

+JH/01 Bugzilla 1201 & 304 - New cutthrough-delivery feature, with TLS support.
+

 Exim version 4.80
 -----------------
 
 Exim version 4.80
 -----------------
 

diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff
index 7efbe6ef449a4497fed39e6fa86ae47f541b3273..aae58c631db548f7b05499c75e97e394b9ef2d64 100644 (file)
--- a/doc/doc-txt/NewStuff
+++ b/doc/doc-txt/NewStuff
@@ -55,6 +55,35 @@ Version 4.81
     process name.  A few other flags used by Sendmail are now accepted and
     ignored.
 
     process name.  A few other flags used by Sendmail are now accepted and
     ignored.
 

+ 7. New cutthrough routing feature.  Requested by a "control = cutthrough_delivery"
+    ACL modifier; works for single-recipient mails which are recieved on and
+    deliverable via SMTP.  Using the connection made for a recipient verify,
+    if requested before the verify, or a new one made for the purpose while
+    the inbound connection is still active.  The bulk of the mail item is copied
+    direct from the inbound socket to the outbound (as well as the spool file).
+    When the source notifies the end of data, the data acceptance by the destination
+    is negociated before the acceptance is sent to the source.  If the destination
+    does not accept the mail item, for example due to content-scanning, the item
+    is not accepted from the source and therefore there is no need to generate
+    a bounce mail.  This is of benefit when providing a secondary-MX service.
+    The downside is that delays are under the control of the ultimate destination
+    system not your own.
+
+    The Recieved-by: header on items delivered by cutthrough is generated
+    early in of reception rather than at the end; this will affect any timestamp
+    included.  The log line showing delivery is recorded before that showing
+    reception; it uses a new ">>" tag instead of "=>".
+    
+    To support the feature, verify-callout connections can now use ESMTP and TLS.
+    The usual smtp transport options are honoured, plus a (new, default everything)
+    hosts_verify_avoid_tls.
+
+    New variable families named tls_in_cipher, tls_out_cipher etc. are introduced
+    for specific access to the information for each connection.  The old names
+    are present for now but deprecated.
+
+    Not yet supported: IGNOREQUOTA, SIZE, PIPELINING, AUTH.
+

 
 Version 4.80
 ------------
 
 Version 4.80
 ------------