+ careful use needs to be made of the conditions in Exim.
+
+ 2. New authenticator driver, "heimdal_gssapi". Server-only.
+ A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
+ is no longer honoured for setuid programs by Heimdal. Use the
+ "server_keytab" option to point to the keytab.
+
+ 3. The "pkg-config" system can now be used when building Exim to reference
+ cflags and library information for lookups and authenticators, rather
+ than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
+ "LOOKUP_LIBS" directly. Similarly for handling the TLS library support
+ without adjusting "TLS_INCLUDE" and "TLS_LIBS".
+
+ In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
+ find the headers and libraries for PCRE.
+
+ 4. New expansion variable $tls_bits.
+
+ 5. New lookup type, "dbmjz". Key is an Exim list, the elements of which will
+ be joined together with ASCII NUL characters to construct the key to pass
+ into the DBM library. Can be used with gsasl to access sasldb2 files as
+ used by Cyrus SASL.
+
+ 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
+
+ Avoid release 1.0.1a if you can. Note that the default value of
+ "openssl_options" is no longer "+dont_insert_empty_fragments", as that
+ increased susceptibility to attack. This may still have interoperability
+ implications for very old clients (see version 4.31 change 37) but
+ administrators can choose to make the trade-off themselves and restore
+ compatibility at the cost of session security.
+
+ 7. Use of the new expansion variable $tls_sni in the main configuration option
+ tls_certificate will cause Exim to re-expand the option, if the client
+ sends the TLS Server Name Indication extension, to permit choosing a
+ different certificate; tls_privatekey will also be re-expanded. You must
+ still set these options to expand to valid files when $tls_sni is not set.
+
+ The SMTP Transport has gained the option tls_sni, which will set a hostname
+ for outbound TLS sessions, and set $tls_sni too.
+
+ A new log_selector, +tls_sni, has been added, to log received SNI values
+ for Exim as a server.
+
+ 8. The existing "accept_8bitmime" option now defaults to true. This means
+ that Exim is deliberately not strictly RFC compliant. We're following
+ Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
+ Those who disagree, or know that they are talking to mail servers that,
+ even today, are not 8-bit clean, need to turn off this option.
+
+ 9. Exim can now be started with -bw (with an optional timeout, given as
+ -bw<timespec>). With this, stdin at startup is a socket that is
+ already listening for connections. This has a more modern name of
+ "socket activation", but forcing the activated socket to fd 0. We're
+ interested in adding more support for modern variants.
+
+10. ${eval } now uses 64-bit values on supporting platforms. A new "G" suffix
+ for numbers indicates multiplication by 1024^3.
+
+11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
+ gnutls_require_mac & gnutls_require_protocols are no longer supported.
+ tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
+ string, documentation for which is at:
+ http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html
+
+ SNI support has been added to Exim's GnuTLS integration too.
+
+ For sufficiently recent GnuTLS libraries, ${randint:..} will now use
+ gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
+
+12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
+ is now available. If the contents of the file are valid, then Exim will
+ send that back in response to a TLS status request; this is OCSP Stapling.
+ Exim will not maintain the contents of the file in any way: administrators
+ are responsible for ensuring that it is up-to-date.
+
+ See "experimental-spec.txt" for more details.
+
+13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
+ identically to TXT record lookups.
+
+14. New expansion variable $tod_epoch_l for higher-precision time.
+
+15. New global option tls_dh_max_bits, defaulting to current value of NSS
+ hard-coded limit of DH ephemeral bits, to fix interop problems caused by
+ GnuTLS 2.12 library recommending a bit count higher than NSS supports.
+
+16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
+ Option can now be a path or an identifier for a standard prime.
+ If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
+ Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
+ primes.