TCP Fast Open

[exim.git] / doc / doc-txt / NewStuff

diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff
index aabeff3383c06427b19bf484222d2846c6aad117..83ee4c3afe86b075721d3e5ecf0c556d1f90900e 100644 (file)
--- a/doc/doc-txt/NewStuff
+++ b/doc/doc-txt/NewStuff
@@ -9,12 +9,59 @@ the documentation is updated, this file is reduced to a short list.
 Version 4.88
 ------------
 
- 1. The new perl_tainmode option allows to run the embedded perl
+ 1. The new perl_taintmode option allows to run the embedded perl
     interpreter in taint mode.
 
- 2. Facility for named queues.  A commandline argument can specify
-    the queue name for a queue-runner, and an ACL modifier can set
-    the queue to be used for a message.
+ 2. New log_selector: dnssec, adds a "DS" tag to acceptance and delivery lines.
+
+ 3. Speculative debugging, via a "kill" option to the "control=debug" ACL
+    modifier.
+
+ 4. New expansion item ${sha3:<string>} / ${sha3_<N>:<string>}.
+    N can be 224, 256 (default), 384, 512.
+    With GnuTLS 3.5.0 or later, only.
+
+ 5. Facility for named queues:  A commandline argument can specify
+    the queue name for a queue operation, and an ACL modifier can set
+    the queue to be used for a message.  A $queue_name variable gives
+    visibility.
+
+ 6. New expansion operators base32/base32d.
+
+ 7. The CHUNKING ESMTP extension from RFC 3030.  May give some slight
+    performance increase and network load decrease.  Main config option
+    chunking_advertise_hosts, and smtp transport option hosts_try_chunking
+    for control.
+
+ 8. LMDB lookup support, as Experimental. Patch supplied by Andrew Colin Kissa.
+
+ 9. Expansion operator escape8bit, like escape but not touching newline etc..
+
+10. Feature macros, generated from compile options.  All start with "_HAVE_"
+    and go on with some roughly recognisable name.  Driver macros, for
+    router, transport and authentication drivers; names starting with "_DRVR_".
+    Option macros, for each configuration-file option; all start with "_OPT_".
+    Use the "-bP macros" command-line option to see what is present.
+
+11. Integer values for options can take a "G" multiplier.
+
+12. defer=pass option for the ACL control cutthrough_delivery, to reflect 4xx
+    returns from the target back to the initiator, rather than spooling the
+    message.
+
+13. New built-in constants available for tls_dhparam and default changed.
+
+14. If built with EXPERIMENTAL_QUEUEFILE, a queuefile transport, for writing
+    out copies of the message spool files for use by 3rd-party scanners.
+
+15. A new option on the smtp transport, hosts_try_fastopen.  If the system
+    supports it (on Linux it must be enabled in the kernel by the sysadmin)
+    try to use RFC 7413 "TCP Fast Open".  No data is sent on the SYN segment
+    but it permits a peer that also supports the facility to send its SMTP
+    banner immediately after the SYN,ACK segment rather then waiting for
+    another ACK - so saving up to one roundtrip time.  Because it requires
+    previous communication with the peer (we save a cookie from it) this
+    will only become active on frequently-contected destinations.
 
 
 Version 4.87