+ 3. When built with SUPPORT_TLS and USE_GNUTLS, the SMTP transport driver now
+ has a "tls_dh_min_bits" option, to set the minimum acceptable number of
+ bits in the Diffie-Hellman prime offered by a server (in DH ciphersuites)
+ acceptable for security. (Option accepted but ignored if using OpenSSL).
+ Defaults to 1024, the old value. May be lowered only to 512, or raised as
+ far as you like. Raising this may hinder TLS interoperability with other
+ sites and is not currently recommended. Lowering this will permit you to
+ establish a TLS session which is not as secure as you might like.
+
+ Unless you really know what you are doing, leave it alone.
+
+ 4. If not built with DISABLE_DNSSEC, Exim now has the main option
+ dns_use_dnssec; if set to 1 then Exim will initialise the resolver library
+ to send the DO flag to your recursive resolver. If you have a recursive
+ resolver, which can set the Authenticated Data (AD) flag in results, Exim
+ can now detect this.
+
+ Current status: work-in-progress; $sender_host_dnssec variable added.
+
+ 5. DSCP support for outbound connections: on a transport using the smtp driver,
+ set "dscp = ef", for instance, to cause the connections to have the relevant
+ DSCP (IPv4 TOS or IPv6 TCLASS) value in the header.
+
+ Similarly for inbound connections, there is a new control modifier, dscp,
+ so "warn control = dscp/ef" in the connect ACL, or after authentication.
+
+ Supported values depend upon system libraries. "exim -bI:dscp" to list the
+ ones Exim knows of. You can also set a raw number 0..0x3F.
+
+ 6. The -G command-line flag is no longer ignored; it is now equivalent to an
+ ACL setting "control = suppress_local_fixups". The -L command-line flag
+ is now accepted and forces use of syslog, with the provided tag as the
+ 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 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.
+
+ 8. New expansion operators ${listnamed:name} to get the content of a named list
+ and ${listcount:string} to count the items in a list.
+
+ 9. New global option "gnutls_enable_pkcs11", defaults false. The GnuTLS
+ rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
+ modules. For some situations this is desirable, but we expect admin in
+ those situations to know they want the feature. More commonly, it means
+ that GUI user modules get loaded and are broken by the setuid Exim being
+ unable to access files specified in environment variables and passed
+ through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
+ unless this new option is set.
+
+10. The "acl = name" condition on an ACL now supports optional arguments.
+ New expansion item "${acl {name}{arg}...}" and expansion condition
+ "acl {{name}{arg}...}" are added. In all cases up to nine arguments
+ can be used, appearing in $acl_arg1 to $acl_arg9 for the called ACL.
+ Variable $acl_narg contains the number of arguments. If the ACL sets
+ a "message =" value this becomes the result of the expansion item,
+ or the value of $value for the expansion condition. If the ACL returns
+ accept the expansion condition is true; if reject, false. A defer
+ return results in a forced fail.
git://git.exim.org / exim.git / blobdiff