+Exim version 4.80
+-----------------
+
+ * BEWARE backwards-incompatible changes in SSL libraries, thus the version
+ bump. See points below for details.
+ Also an LDAP data returned format change.
+
+ * The value of $tls_peerdn is now print-escaped when written to the spool file
+ in a -tls_peerdn line, and unescaped when read back in. We received reports
+ of values with embedded newlines, which caused spool file corruption.
+
+ If you have a corrupt spool file and you wish to recover the contents after
+ upgrading, then lock the message, replace the new-lines that should be part
+ of the -tls_peerdn line with the two-character sequence \n and then unlock
+ the message. No tool has been provided as we believe this is a rare
+ occurence.
+
+ * With OpenSSL 1.0.1+, Exim now supports TLS 1.1 and TLS 1.2. If built
+ against 1.0.1a then you will get a warning message and the
+ "openssl_options" value will not parse "no_tlsv1_1": the value changes
+ incompatibly between 1.0.1a and 1.0.1b, because the value chosen for 1.0.1a
+ is infelicitous. We advise avoiding 1.0.1a.
+
+ "openssl_options" gains "no_tlsv1_1", "no_tlsv1_2" and "no_compression".
+
+ COMPATIBILITY WARNING: The default value of "openssl_options" is no longer
+ "+dont_insert_empty_fragments". We default to unset. That old default was
+ grandfathered in from before openssl_options became a configuration option.
+ Empty fragments are inserted by default through TLS1.0, to partially defend
+ against certain attacks; TLS1.1+ change the protocol so that this is not
+ needed. The DIEF SSL option was required for some old releases of mail
+ clients which did not gracefully handle the empty fragments, and was
+ initially set in Exim release 4.31 (see ChangeLog, item 37).
+
+ If you still have affected mail-clients, and you see SSL protocol failures
+ with this release of Exim, set:
+ openssl_options = +dont_insert_empty_fragments
+ in the main section of your Exim configuration file. You're trading off
+ security for compatibility. Exim is now defaulting to higher security and
+ rewarding more modern clients.
+
+ If the option tls_dhparams is set and the parameters loaded from the file
+ have a bit-count greater than the new option tls_dh_max_bits, then the file
+ will now be ignored. If this affects you, raise the tls_dh_max_bits limit.
+ We suspect that most folks are using dated defaults and will not be affected.
+
+ * Ldap lookups returning multi-valued attributes now separate the attributes
+ with only a comma, not a comma-space sequence. Also, an actual comma within
+ a returned attribute is doubled. This makes it possible to parse the
+ attribute as a comma-separated list. Note the distinction from multiple
+ attributes being returned, where each one is a name=value pair.
+
+ If you are currently splitting the results from LDAP upon a comma, then you
+ should check carefully to see if adjustments are needed.
+
+ This change lets cautious folks distinguish "comma used as separator for
+ joining values" from "comma inside the data".
+
+ * accept_8bitmime now defaults on, which is not RFC compliant but is better
+ suited to today's Internet. See http://cr.yp.to/smtp/8bitmime.html for a
+ sane rationale. Those who wish to be strictly RFC compliant, or know that
+ they need to talk to servers that are not 8-bit-clean, now need to take
+ explicit configuration action to default this option off. This is not a
+ new option, you can safely force it off before upgrading, to decouple
+ configuration changes from the binary upgrade while remaining RFC compliant.
+
+ * The GnuTLS support has been mostly rewritten, to use APIs which don't cause
+ deprecation warnings in GnuTLS 2.12.x. As part of this, these three options
+ are no longer supported:
+
+ gnutls_require_kx
+ gnutls_require_mac
+ gnutls_require_protocols
+
+ Their functionality is entirely subsumed into tls_require_ciphers. In turn,
+ tls_require_ciphers is no longer an Exim list and is not parsed by Exim, but
+ is instead given to gnutls_priority_init(3), which expects a priority string;
+ this behaviour is much closer to the OpenSSL behaviour. See:
+
+ http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html
+
+ for fuller documentation of the strings parsed. The three gnutls_require_*
+ options are still parsed by Exim and, for this release, silently ignored.
+ A future release will add warnings, before a later still release removes
+ parsing entirely and the presence of the options will be a configuration
+ error.
+
+ Note that by default, GnuTLS will not accept RSA-MD5 signatures in chains.
+ A tls_require_ciphers value of NORMAL:%VERIFY_ALLOW_SIGN_RSA_MD5 may
+ re-enable support, but this is not supported by the Exim maintainers.
+ Our test suite no longer includes MD5-based certificates.
+
+ This rewrite means that Exim will continue to build against GnuTLS in the
+ future, brings Exim closer to other GnuTLS applications and lets us add
+ support for SNI and other features more readily. We regret that it wasn't
+ feasible to retain the three dropped options.
+
+ * If built with TLS support, then Exim will now validate the value of
+ the main section tls_require_ciphers option at start-up. Before, this
+ would cause a STARTTLS 4xx failure, now it causes a failure to start.
+ Running with a broken configuration which causes failures that may only
+ be left in the logs has been traded off for something more visible. This
+ change makes an existing problem more prominent, but we do not believe
+ anyone would deliberately be running with an invalid tls_require_ciphers
+ option.
+
+ This also means that library linkage issues caused by conflicts of some
+ kind might take out the main daemon, not just the delivery or receiving
+ process. Conceivably some folks might prefer to continue delivering
+ mail plaintext when their binary is broken in this way, if there is a
+ server that is a candidate to receive such mails that does not advertise
+ STARTTLS. Note that Exim is typically a setuid root binary and given
+ broken linkage problems that cause segfaults, we feel it is safer to
+ fail completely. (The check is not done as root, to ensure that problems
+ here are not made worse by the check).
+
+
+Exim version 4.77
+-----------------
+
+ * GnuTLS will now attempt to use TLS 1.2 and TLS 1.1 before TLS 1.0 and SSL3,
+ if supported by your GnuTLS library. Use the existing
+ "gnutls_require_protocols" option to downgrade this if that will be a
+ problem. Prior to this release, supported values were "TLS1" and "SSL3",
+ so you should be able to update configuration prior to update.
+
+ [nb: gnutls_require_protocols removed in Exim 4.80, instead use
+ tls_require_ciphers to provide a priority string; see notes above]
+
+ * The match_<type>{string1}{string2} expansion conditions no longer subject
+ string2 to string expansion, unless Exim was built with the new
+ "EXPAND_LISTMATCH_RHS" option. Too many people have inadvertently created
+ insecure configurations that way. If you need the functionality and turn on
+ that build option, please let the developers know, and know why, so we can
+ try to provide a safer mechanism for you.
+
+ The match{}{} expansion condition (for regular expressions) is NOT affected.
+ For match_<type>{s1}{s2}, all list functionality is unchanged. The only
+ change is that a '$' appearing in s2 will not trigger expansion, but instead
+ will be treated as a literal $ sign; the effect is very similar to having
+ wrapped s2 with \N...\N. If s2 contains a named list and the list definition
+ uses $expansions then those _will_ be processed as normal. It is only the
+ point at which s2 is read where expansion is inhibited.
+
+ If you are trying to test if two email addresses are equal, use eqi{s1}{s2}.
+ If you are testing if the address in s1 occurs in the list of items given
+ in s2, either use the new inlisti{s1}{s2} condition (added in 4.77) or use
+ the pre-existing forany{s2}{eqi{$item}{s1}} condition.
+
+
+Exim version 4.74
+-----------------
+
+ * The integrated support for dynamically loadable lookup modules has an ABI
+ change from the modules supported by some OS vendors through an unofficial
+ patch. Don't try to mix & match.
+
+ * Some parts of the build system are now beginning to assume that the host
+ environment is POSIX. If you're building on a system where POSIX tools are
+ not the default, you might have an easier time if you switch to the POSIX
+ tools. Feel free to report non-POSIX issues as a request for a feature
+ enhancement, but if the POSIX variants are available then the fix will
+ probably just involve some coercion. See the README instructions for
+ building on such hosts.
+
+
+Exim version 4.73
+-----------------
+
+ * The Exim run-time user can no longer be root; this was always
+ strongly discouraged, but is now prohibited both at build and
+ run-time. If you need Exim to run routinely as root, you'll need to
+ patch the source and accept the risk. Here be dragons.
+
+ * Exim will no longer accept a configuration file owned by the Exim
+ run-time user, unless that account is explicitly the value in
+ CONFIGURE_OWNER, which we discourage. Exim now checks to ensure that
+ files are not writeable by other accounts.
+
+ * The ALT_CONFIG_ROOT_ONLY build option is no longer optional and is forced
+ on; the Exim user can, by default, no longer use -C/-D and retain privilege.
+ Two new build options mitigate this.
+
+ * TRUSTED_CONFIG_LIST defines a file containing a whitelist of config
+ files that are trusted to be selected by the Exim user; one per line.
+ This is the recommended approach going forward.
+
+ * WHITELIST_D_MACROS defines a colon-separated list of macro names which
+ the Exim run-time user may safely pass without dropping privileges.
+ Because changes to this involve a recompile, this is not the recommended
+ approach but may ease transition. The values of the macros, when
+ overridden, are constrained to match this regex: ^[A-Za-z0-9_/.-]*$
+
+ * The system_filter_user option now defaults to the Exim run-time user,
+ rather than root. You can still set it explicitly to root and this
+ can be done with prior versions too, letting you roll versions
+ without needing to change this configuration option.
+
+ * ClamAV must be at least version 0.95 unless WITH_OLD_CLAMAV_STREAM is
+ defined at build time.
+
+
+Exim version 4.70
+-----------------
+
+1. Experimental Yahoo! Domainkeys support has been dropped in this release.
+It has been superceded by a native implementation of its successor DKIM.
+
+2. Up to version 4.69, Exim came with an embedded version of the PCRE library.
+As of 4.70, this is no longer the case. To compile Exim, you will need PCRE
+installed. Most OS distributions have ready-made library and development
+packages.
+
+
+Exim version 4.68
+-----------------
+
+1. The internal implementation of the database keys that are used for ACL
+ratelimiting has been tidied up. This means that an update to 4.68 might cause
+Exim to "forget" previous rates that it had calculated, and reset them to zero.
+
+
+Exim version 4.64
+-----------------
+
+1. Callouts were setting the name used for EHLO/HELO from $smtp_active_
+hostname. This is wrong, because it relates to the incoming message (and
+probably the interface on which it is arriving) and not to the outgoing
+callout (which could be using a different interface). This has been
+changed to use the value of the helo_data option from the smtp transport
+instead - this is what is used when a message is actually being sent. If
+there is no remote transport (possible with a router that sets up host
+addresses), $smtp_active_hostname is used. This change is mentioned here in
+case somebody is relying on the use of $smtp_active_hostname.
+
+2. A bug has been fixed that might just possibly be something that is relied on
+in some configurations. In expansion items such as ${if >{xxx}{yyy}...} an
+empty string (that is {}) was being interpreted as if it was {0} and therefore
+treated as the number zero. From release 4.64, such strings cause an error
+because a decimal number, possibly followed by K or M, is required (as has
+always been documented).
+
+3. There has been a change to the GnuTLS support (ChangeLog/PH/20) to improve
+Exim's performance. Unfortunately, this has the side effect of being slightly
+non-upwards compatible for versions 4.50 and earlier. If you are upgrading from
+one of these earlier versions and you use GnuTLS, you must remove the file
+called gnutls-params in Exim's spool directory. If you don't do this, you will
+see this error:
+
+ TLS error on connection from ... (DH params import): Base64 decoding error.
+
+Removing the file causes Exim to recompute the relevant encryption parameters
+and cache them in the new format that was introduced for release 4.51 (May
+2005). If you are upgrading from release 4.51 or later, there should be no
+problem.
+
+
+Exim version 4.63
+-----------------
+
+When an SMTP error message is specified in a "message" modifier in an ACL, or
+in a :fail: or :defer: message in a redirect router, Exim now checks the start
+of the message for an SMTP error code. This consists of three digits followed
+by a space, optionally followed by an extended code of the form n.n.n, also
+followed by a space. If this is the case and the very first digit is the same
+as the default error code, the code from the message is used instead. If the
+very first digit is incorrect, a panic error is logged, and the default code is
+used. This is an incompatible change, but it is not expected to affect many (if
+any) configurations. It is possible to suppress the use of the supplied code in
+a redirect router by setting the smtp_error_code option false. In this case,
+any SMTP code is quietly ignored.
+
+
+Exim version 4.61
+-----------------
+
+1. The default number of ACL variables of each type has been increased to 20,
+and it's possible to compile Exim with more. You can safely upgrade to this
+release if you already have messages on the queue with saved ACL variable
+values. However, if you downgrade from this release with messages on the queue,
+any saved ACL values they may have will be lost.
+
+2. The default value for rfc1413_query_timeout has been changed from 30s to 5s.
+
+
+Exim version 4.54
+-----------------
+
+There was a problem with 4.52/TF/02 in that a "name=" option on control=
+submission terminated at the next slash, thereby not allowing for slashes in
+the name. This has been changed so that "name=" takes the rest of the string as
+its data. It must therefore be the last option.
+
+
+Version 4.53
+------------
+
+If you are using the experimental Domain Keys support, you must upgrade to
+at least libdomainkeys 0.67 in order to run this release of Exim.
+
+
+Version 4.51
+------------
+
+1. The format in which GnuTLS parameters are cached (in the file gnutls-params
+in the spool directory) has been changed. The new format can also be generated
+externally, so it is now possible to update the values from outside Exim. This
+has been implemented in an upwards, BUT NOT downwards, compatible manner.
+Upgrading should be seamless: when Exim finds that it cannot understand an
+existing cache file, it generates new parameters and writes them to the cache
+in the new format. If, however, you downgrade from 4.51 to a previous release,
+you MUST delete the gnutls-params file in the spool directory, because the
+older Exim will not recognize the new format.
+
+2. When doing a callout as part of verifying an address, Exim was not paying
+attention to any local part prefix or suffix that was matched by the router
+that accepted the address. It now behaves in the same way as it does for
+delivery: the affixes are removed from the local part unless
+rcpt_include_affixes is set on the transport. If you have a configuration that
+uses prefixes or suffixes on addresses that could be used for callouts, and you
+want the affixes to be retained, you must make sure that rcpt_include_affixes
+is set on the transport.
+
+3. Bounce and delay warning messages no longer contain details of delivery
+errors, except for explicit messages (e.g. generated by :fail:) and SMTP
+responses from remote hosts.
+
+