- 1. There is a new Boolean global option called mua_wrapper, defaulting false.
- This causes Exim to run an a restricted mode, in order to provide a very
- specific service.
-
- Background: On a personal computer, it is a common requirement for all
- email to be sent to a smarthost. There are plenty of MUAs that can be
- configured to operate that way, for all the popular operating systems.
- However, there are MUAs for Unix-like systems that cannot be so configured:
- they submit messages using the command line interface of
- /usr/sbin/sendmail. In addition, utility programs such as cron submit
- messages this way.
-
- Requirement: The requirement is for something that can provide the
- /usr/sbin/sendmail interface and deliver messages to a smarthost, but not
- provide any queueing or retrying facilities. Furthermore, the delivery to
- the smarthost should be synchronous, so that if it fails, the sending MUA
- is immediately informed. In other words, we want something that in effect
- converts a command-line MUA into a TCP/SMTP MUA.
-
- Solutions: There are a number of applications (for example, ssmtp) that do
- this job. However, people have found them to be lacking in various ways.
- For instance, some sites want to allow aliasing and forwarding before
- sending to the smarthost.
-
- Using Exim: Exim already had the necessary infrastructure for doing this
- job. Just a few tweaks were needed to make it behave as required, though it
- is somewhat of an overkill to use a fully-featured MTA for this purpose.
-
- Setting mua_wrapper=true causes Exim to run in a special mode where it
- assumes that it is being used to "wrap" a command-line MUA in the manner
- just described.
-
- If you set mua_wrapper=true, you also need to provide a compatible router
- and transport configuration. Typically there will be just one router and
- one transport, sending everything to a smarthost.
-
- When run in MUA wrapping mode, the behaviour of Exim changes in the
- following ways:
-
- (a) A daemon cannot be run, nor will Exim accept incoming messages from
- inetd. In other words, the only way to submit messages is via the
- command line.
-
- (b) Each message is synchonously delivered as soon as it is received (-odi
- is assumed). All queueing options (queue_only, queue_smtp_domains,
- control=queue, control=freeze in an ACL etc.) are quietly ignored. The
- Exim reception process does not finish until the delivery attempt is
- complete. If the delivery was successful, a zero return code is given.
-
- (c) Address redirection is permitted, but the final routing for all
- addresses must be to the same remote transport, and to the same list of
- hosts. Furthermore, the return_address must be the same for all
- recipients, as must any added or deleted header lines. In other words,
- it must be possible to deliver the message in a single SMTP
- transaction, however many recipients there are.
-
- (d) If the conditions in (c) are not met, or if routing any address results
- in a failure or defer status, or if Exim is unable to deliver all the
- recipients successfully to one of the hosts immediately, delivery of
- the entire message fails.
-
- (e) Because no queueing is allowed, all failures are treated as permanent;
- there is no distinction between 4xx and 5xx SMTP response codes from
- the smarthost. Furthermore, because only a single yes/no response can
- be given to the caller, it is not possible to deliver to some
- recipients and not others. If there is an error (temporary or
- permanent) for any recipient, all are failed.
-
- (f) If more than one host is listed, Exim will try another host after a
- connection failure or a timeout, in the normal way. However, if this
- kind of failure happens for all the hosts, the delivery fails.
-
- (g) When delivery fails, an error message is written to the standard error
- stream (as well as to Exim's log), and Exim exits to the caller with a
- return code value 1. The message is expunged from Exim's spool files.
- No bounce messages are ever generated.
-
- (h) No retry data is maintained, and any retry rules are ignored.
-
- (i) A number of Exim options are overridden: deliver_drop_privilege is
- forced true, max_rcpt in the smtp transport is forced to "unlimited",
- remote_max_parallel is forced to one, and fallback hosts are ignored.
-
- The overall effect is that Exim makes a single synchronous attempt to
- deliver the message, failing if there is any kind of problem. Because no
- local deliveries are done and no daemon can be run, Exim does not need root
- privilege. It should be possible to run it setuid=exim instead of
- setuid=root. See section 48.3 in the 4.40 manual for a general discussion
- about the advantages and disadvantages of running without root privilege.
-
- 2. There have been problems with DNS servers when SRV records are looked up.
- Some mis-behaving servers return a DNS error or timeout when a non-existent
- SRV record is sought. Similar problems have in the past been reported for
- MX records. The global dns_again_means_nonexist option can help with this
- problem, but it is heavy-handed because it is a global option. There are
- now two new options for the dnslookup router. They are called
- srv_fail_domains and mx_fail_domains. In each case, the value is a domain
- list. If an attempt to look up an SRV or MX record results in a DNS failure
- or "try again" response, and the domain matches the relevant list, Exim
- behaves as if the DNS had responded "no such record". In the case of an SRV
- lookup, this means that the router proceeds to look for MX records; in the
- case of an MX lookup, it proceeds to look for A or AAAA records, unless the
- domain matches mx_domains.
-
- 3. The following functions are now available in the local_scan() API:
-
- (a) void header_remove(int occurrence, uschar *name)
-
- This function removes header lines. If "occurrence" is zero or negative,
- all occurrences of the header are removed. If occurrence is greater
- than zero, that particular instance of the header is removed. If no
- header(s) can be found that match the specification, the function does
- nothing.
-
- (b) BOOL header_testname(header_line *hdr, uschar *name, int length,
- BOOL notdel)
-
- This function tests whether the given header has the given name. It
- is not just a string comparison, because whitespace is permitted
- between the name and the colon. If the "notdel" argument is TRUE, a
- FALSE return is forced for all "deleted" headers; otherwise they are
- not treated specially. For example:
-
- if (header_testname(h, US"X-Spam", 6, TRUE)) ...
-
- (c) void header_add_at_position(BOOL after, uschar *name, BOOL topnot,
- int type, char *format, ...)
-
- This function adds a new header line at a specified point in the header
- chain. If "name" is NULL, the new header is added at the end of the
- chain if "after" is TRUE, or at the start if "after" is FALSE. If
- "name" is not NULL, the headers are searched for the first non-deleted
- header that matches the name. If one is found, the new header is added
- before it if "after" is FALSE. If "after" is true, the new header is
- added after the found header and any adjacent subsequent ones with the
- same name (even if marked "deleted"). If no matching non-deleted header
- is found, the "topnot" option controls where the header is added. If it
- is TRUE, addition is at the top; otherwise at the bottom. Thus, to add
- a header after all the Received: headers, or at the top if there are no
- Received: headers, you could use
-
- header_add_at_position(TRUE, US"Received", TRUE, ' ', "X-xxx: ...");
-
- Normally, there is always at least one non-deleted Received: header,
- but there may not be if received_header_text expands to an empty
- string.
-
- (d) BOOL receive_remove_recipient(uschar *recipient)
-
- This is a convenience function to remove a named recipient from the
- list of recipients. It returns TRUE if a recipient was removed, and
- FALSE if no matching recipient could be found. The argument must be a
- complete email address.
-
- 4. When an ACL "warn" statement adds one or more header lines to a message,
- they are added at the end of the existing header lines by default. It is
- now possible to specify that any particular header line should be added
- right at the start (before all the Received: lines) or immediately after
- the first block of Received: lines in the message. This is done by
- specifying :at_start: or :after_received: (or, for completeness, :at_end:)
- before the text of the header line. (Header text cannot start with a colon,
- as there has to be a header name first.) For example:
-
- warn message = :after_received:X-My-Header: something or other...
-
- If more than one header is supplied in a single warn statement, each one is
- treated independently and can therefore be placed differently. If you add
- more than one line at the start, or after the Received: block, they will
- end up in reverse order.
-
- Warning: This facility currently applies only to header lines that are
- added in an ACL. It does NOT work for header lines that are added in a
- system filter or in a router or transport.
-
- 5. There is now a new error code that can be used in retry rules. Its name is
- "rcpt_4xx", and there are three forms. A literal "rcpt_4xx" matches any 4xx
- error received for an outgoing SMTP RCPT command; alternatively, either the
- first or both of the x's can be given as digits, for example: "rcpt_45x" or
- "rcpt_436". If you want (say) to recognize 452 errors given to RCPT
- commands by a particular host, and have only a one-hour retry for them, you
- can set up a retry rule of this form:
-
- the.host.name rcpt_452 F,1h,10m
-
- Naturally, this rule must come before any others that would match.
-
- These new errors apply to both outgoing SMTP (the smtp transport) and
- outgoing LMTP (either the lmtp transport, or the smtp transport in LMTP
- mode). Note, however, that they apply only to responses to RCPT commands.
-
- 6. The "postmaster" option of the callout feature of address verification has
- been extended to make it possible to use a non-empty MAIL FROM address when
- checking a postmaster address. The new suboption is called "postmaster_
- mailfrom", and you use it like this:
-
- require verify = sender/callout=postmaster_mailfrom=abc@x.y.z
-
- Providing this suboption causes the postmaster check to be done using the
- given address. The original "postmaster" option is equivalent to
-
- require verify = sender/callout=postmaster_mailfrom=
-
- If both suboptions are present, the rightmost one overrides.
-
- Important notes:
-
- (1) If you use a non-empty sender address for postmaster checking, there is
- the likelihood that the remote host will itself initiate a callout
- check back to your host to check that address. As this is a "normal"
- callout check, the sender will most probably be empty, thus avoiding
- possible callout loops. However, to be on the safe side it would be
- best to set up your own ACLs so that they do not do sender verification
- checks when the recipient is the address you use for postmaster callout
- checking.
-
- (2) The caching arrangements for postmaster checking do NOT take account of
- the sender address. It is assumed that either the empty address, or a
- fixed non-empty address will be used. All that Exim remembers is that
- the postmaster check for the domain succeeded or failed.
-
- 7. When verifying addresses in header lines using the verify=header_sender
- option, Exim behaves by default as if the addresses are envelope sender
- addresses from a message. Callout verification therefore tests to see
- whether a bounce message could be delivered, by using an empty address in
- the MAIL FROM command. However, it is arguable that these addresses might
- never be used as envelope senders, and could therefore justifiably reject
- bounce messages (empty senders). There is now an additional callout option
- for verify=header_sender that allows you to specify what address to use in
- the MAIL FROM command. You use it as in this example:
-
- require verify = header_sender/callout=mailfrom=abcd@x.y.z
-
- Important notes:
-
- (1) As in the case of postmaster_mailfrom (see above), you should think
- about possible loops.
-
- (2) In this case, as in the case of recipient callouts with non-empty
- senders (the use_sender option), caching is done on the basis of a
- recipient/sender pair.
-
- 8. If you build Exim with USE_READLINE=yes in Local/Makefile, it will try to
- load libreadline dynamically whenever the -be (test expansion) option is
- used without command line arguments. If successful, it will then use
- readline() for reading the test data. A line history is supported. By the
- time Exim does this, it is running as the calling user, so this should not
- cause any security problems. Security is the reason why this is NOT
- supported for -bt or -bv, when Exim is running as root or exim,
- respectively. Note that this option adds to the size of the Exim binary,
- because the dynamic loading library is not otherwise included. On my
- desktop it adds about 2.5K. You may need to add -ldl to EXTRA_LIBS when you
- set USE_READLINE=yes.
-
- 9. Added ${str2b64:<string>} to the expansion operators. This operator
- converts an arbitrary string into one that is base64 encoded.
-
-10. A new authenticator, called cyrus_sasl, has been added. This requires
- the presence of the Cyrus SASL library; it authenticates by calling this
- library, which supports a number of authentication mechanisms, including
- PLAIN and LOGIN, but also several others that Exim does not support
- directly. The code for this authenticator was provided by Matthew
- Byng-Maddick of A L Digital Ltd (http://www.aldigital.co.uk). Here follows
- draft documentation:
-
- xx. THE CYRUS_SASL AUTHENTICATOR
-
- The cyrus_sasl authenticator provides server support for the Cyrus library
- Implementation of the RFC 2222 "Simple Authentication and Security Layer".
- It provides a gatewaying mechanism directly to the Cyrus interface, so if
- your Cyrus library can do, for example, CRAM-MD5, then so can the
- cyrus_sasl authenticator. By default it uses the public name of the driver
- to determine which mechanism to support.
-
- Where access to some kind of secret file is required, for example in GSSAPI
- or CRAM-MD5, it is worth noting that the authenticator runs as the exim
- user, and that the Cyrus SASL library has no way of escalating privileges
- by default. You may also find you need to set environment variables,
- depending on the driver you are using.
-
- xx.1 Using cyrus_sasl as a server
-
- The cyrus_sasl authenticator has four private options. It puts the username
- (on a successful authentication) into $1.
-
- server_hostname Type: string* Default: $primary_hostname
-
- This option selects the hostname that is used when communicating with
- the library. It is up to the underlying SASL plug-in what it does with
- this data.
-
- server_mech Type: string Default: public_name
-
- This option selects the authentication mechanism this driver should
- use. It allows you to use a different underlying mechanism from the
- advertised name. For example:
-
- sasl:
- driver = cyrus_sasl
- public_name = X-ANYTHING
- server_mech = CRAM-MD5
- server_set_id = $1
-
- server_realm Type: string Default: unset
-
- This is the SASL realm that the server is claiming to be in.
-
- server_service Type: string Default: "smtp"
-
- This is the SASL service that the server claims to implement.
-
- For straigthforward cases, you do not need to set any of the
- authenticator's private options. All you need to do is to specify an
- appropriate mechanism as the public name. Thus, if you have a SASL library
- that supports CRAM-MD5 and PLAIN, you might have two authenticators as
- follows:
-
- sasl_cram_md5:
- driver = cyrus_sasl
- public_name = CRAM-MD5
- server_set_id = $1
-
- sasl_plain:
- driver = cyrus_sasl
- public_name = PLAIN
- server_set_id = $1
-
-11. There is a new global option called tls_on_connect_ports. Its value must be
- a list of port numbers; the most common use is expected to be
-
- tls_on_connect_ports = 465
-
- Setting this option has the same effect as -tls-on-connect on the command
- line, but only for the specified ports. It applies to all connections, both
- via the daemon and via inetd. You still need to specify all the ports for
- the daemon (using daemon_smtp_ports or local_interfaces or the -X command
- line option) because this option does not add an extra port -- rather, it
- specifies different behaviour on a port that is defined elsewhere. The
- -tls-on-connect command line option overrides tls_on_connect_ports, and
- forces tls-on-connect for all ports.
-
-12. There is a new ACL that is run when a DATA command is received, before the
- data itself is received. The ACL is defined by acl_smtp_predata. (Compare
- acl_smtp_data, which is run after the data has been received.)
- This new ACL allows a negative response to be given to the DATA command
- itself. Header lines added by MAIL or RCPT ACLs are not visible at this
- time, but any that are defined here are visible when the acl_smtp_data ACL
- is run.
-
-13. The "control=submission" ACL modifier has an option "/domain=xxx" which
- specifies the domain to be used when creating From: or Sender: lines using
- the authenticated id as a local part. If the option is supplied with an
- empty domain, that is, just "/domain=", Exim assumes that the authenticated
- id is a complete email address, and it uses it as is when creating From:
- or Sender: lines.
-
-14. It is now possible to make retry rules that apply only when the failing
- message has a specific sender. In particular, this can be used to define
- retry rules that apply only to bounce messages. The syntax is to add a new
- third item to a retry rule, of the form "senders=<address list>". The retry
- timings themselves then become the fourth item. For example:
-
- * * senders=: F,1h,30m
-
- would match all bounce messages. If the address list contains white space,
- it must be enclosed in quotes. For example:
-
- a.domain timeout senders="x@b.dom : y@c.dom" G,8h,10m,1.5
-
- When testing retry rules using -brt, you can supply a sender using the -f
- command line option, like this:
-
- exim -f "" -brt user@dom.ain
-
- If you do not set -f with -brt, a retry rule that contains a senders list
- will never be matched.
-
-15. Two new control modifiers have been added to ACLs: "control = enforce_sync"
- and "control = no_enforce_sync". This makes it possible to be selective
- about when SMTP synchronization is enforced. The global option
- smtp_enforce_sync now specifies the default state of the switch. These
- controls can appear in any ACL, but the most obvious place to put them is
- in the ACL defined by acl_smtp_connect, which is run at the start of an
- incoming SMTP connection, before the first synchronization check.
-
-16. Another two new control modifiers are "control = caseful_local_part" and
- "control = caselower_local_part". These are permitted only in the ACL
- specified by acl_smtp_rcpt (i.e. during RCPT processing). By default, the
- contents of $local_part are lower cased before ACL processing.
- After "control = caseful_local_part", any uppercase letters in the original
- local part are restored in $local_part for the rest of the ACL, or until
- "control = caselower_local_part" is encountered. However, this applies only
- to local part handling that takes place directly in the ACL (for example,
- as a key in lookups). If a "verify = recipient" test is obeyed, the
- case-related handling of the local part during the verification is
- controlled by the router configuration (see the caseful_local_part generic
- router option).
-
- This facility could be used, for example, to add a spam score to local
- parts containing upper case letters. For example, using $acl_m4 to
- accumulate the spam score:
-
- warn control = caseful_local_part
- set acl_m4 = ${eval:\
- $acl_m4 + \
- ${if match{$local_part}{[A-Z]}{1}{0}}\
- }
- control = caselower_local_part
-
- Notice that we put back the lower cased version afterwards, assuming that
- is what is wanted for subsequent tests.
-
-17. The option hosts_connection_nolog is provided so that certain hosts can be
- excepted from logging when the +smtp_connection log selector is set. For
- example, you might want not to log SMTP connections from local processes,
- or from 127.0.0.1, or from your local LAN. The option is a host list with
- an unset default. Because it is consulted in the main loop of the daemon,
- you should strive to restrict its value to a short inline list of IP
- addresses and networks. To disable logging SMTP connections from local
- processes, you must create a host list with an empty item. For example:
-
- hosts_connection_nolog = :
-
- If the +smtp_connection log selector is not set, this option has no effect.
-
-18. There is now an acl called acl_smtp_quit, which is run for the QUIT
- command. The outcome of the ACL does not affect the response code to QUIT,
- which is always 221. Thus, the ACL does not in fact control any access.
- For this reason, the only verbs that are permitted are "accept" and "warn".
-
- The ACL can be used for tasks such as custom logging at the end of an SMTP
- session. For example, you can use ACL variables in other ACLs to count
- messages, recipients, etc., and log the totals at QUIT time using one or
- more "logwrite" modifiers on a "warn" command.
-
- You do not need to have a final "accept", but if you do, you can use a
- "message" modifier to specify custom text that is sent as part of the 221
- response.
-
- This ACL is run only for a "normal" QUIT. For certain kinds of disastrous
- failure (for example, failure to open a log file, or when Exim is bombing
- out because it has detected an unrecoverable error), all SMTP commands
- from the client are given temporary error responses until QUIT is received
- or the connection is closed. In these special cases, the ACL is not run.
-
-19. The appendfile transport has two new options, mailbox_size and mailbox_
- filecount. If either these options are set, it is expanded, and the result
- is taken as the current size of the mailbox or the number of files in the
- mailbox, respectively. This makes it possible to use some external means of
- maintaining the data about the size of a mailbox for enforcing quota
- limits. The result of expanding these option values must be a decimal
- number, optionally followed by "K" or "M".
-
-20. It seems that there are broken clients in use that cannot handle multiline
- SMTP responses. Can't people who implement these braindead programs read?
- RFC 821 mentions multiline responses, and it is over 20 years old. They
- must handle multiline responses for EHLO, or do they still use HELO?
- Anyway, here is YAWFAB (yet another workaround for asinine brokenness).
- There's a new ACL switch that can be set by
-
- control = no_multiline_responses
-
- If this is set, it suppresses multiline SMTP responses from ACL rejections.
- One way of doing this would have been just to put out these responses as
- one long line. However, RFC 2821 specifies a maximum of 512 bytes per
- response ("use multiline responses for more" it says), and some of the
- responses might get close to that. So I have implemented this by doing two
- very easy things:
-
- (1) Extra information that is normally output as part of a rejection
- caused by sender verification failure is omitted. Only the final line
- (typically "sender verification failed") is now sent.
-
- (2) If a "message" modifier supplies a multiline response, only the first
- line is output.
-
- The setting of the switch can, of course, be made conditional on the
- calling host.
-
-21. There is now support for the libradius library that comes with FreeBSD.
- This is an alternative to the radiusclient library that Exim already
- supports. To use the FreeBSD library, you need to set
-
- RADIUS_LIB_TYPE=RADLIB
-
- in Local/Makefile, in addition to RADIUS_CONFIGURE_FILE, and you probably
- also need -libradius in EXTRALIBS.
-
-
-Version 4.42
+ 1. New command-line option -bI:sieve will list all supported sieve extensions
+ of this Exim build on standard output, one per line.
+ ManageSieve (RFC 5804) providers managing scripts for use by Exim should
+ query this to establish the correct list to include in the protocol's
+ SIEVE capability line.
+
+ 2. If the -n option is combined with the -bP option, then the name of an
+ emitted option is not output, only the value (if visible to you).
+ For instance, "exim -n -bP pid_file_path" should just emit a pathname
+ followed by a newline, and no other text.
+
+ 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_dnssec_ok; 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. Exim does not perform validation itself, instead
+ relying upon a trusted path to the resolver.
+
+ 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 received 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 negotiated 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 Received-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.
+
+ 8. New expansion operators ${listnamed:name} to get the content of a named list
+ and ${listcount:string} to count the items in a list.
+
+ 9. New global option "gnutls_allow_auto_pkcs11", defaults false. The GnuTLS
+ rewrite in 4.80 combines with GnuTLS 2.12.0 or later, to autoload PKCS11
+ modules. For some situations this is desirable, but we expect admin in
+ those situations to know they want the feature. More commonly, it means
+ that GUI user modules get loaded and are broken by the setuid Exim being
+ unable to access files specified in environment variables and passed
+ through, thus breakage. So we explicitly inhibit the PKCS11 initialisation
+ unless this new option is set.
+
+ Some older OS's with earlier versions of GnuTLS might not have pkcs11 ability,
+ so have also added a build option which can be used to build Exim with GnuTLS
+ but without trying to use any kind of PKCS11 support. Uncomment this in the
+ Local/Makefile:
+
+ AVOID_GNUTLS_PKCS11=yes
+
+10. The "acl = name" condition on an ACL now supports optional arguments.
+ New expansion item "${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.
+
+11. Routers and transports can now have multiple headers_add and headers_remove
+ option lines. The concatenated list is used.
+
+12. New ACL modifier "remove_header" can remove headers before message gets
+ handled by routers/transports.
+
+13. New dnsdb lookup pseudo-type "a+". A sequence of "a6" (if configured),
+ "aaaa" and "a" lookups is done and the full set of results returned.
+
+14. New expansion variable $headers_added with content from ACL add_header
+ modifier (but not yet added to message).
+
+15. New 8bitmime status logging option for received messages. Log field "M8S".
+
+16. New authenticated_sender logging option, adding to log field "A".
+
+17. New expansion variables $router_name and $transport_name. Useful
+ particularly for debug_print as -bt command-line option does not
+ require privilege whereas -d does.
+
+18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
+ proposed extension to SMTP from Eric Hall.
+
+19. The pipe transport has gained the force_command option, to allow
+ decorating commands from user .forward pipe aliases with prefix
+ wrappers, for instance.
+
+20. Callout connections can now AUTH; the same controls as normal delivery
+ connections apply.
+
+21. Support for DMARC, using opendmarc libs, can be enabled. It adds new
+ options: dmarc_forensic_sender, dmarc_history_file, and dmarc_tld_file.
+ It adds new expansion variables $dmarc_ar_header, $dmarc_status,
+ $dmarc_status_text, and $dmarc_used_domain. It adds a new acl modifier
+ dmarc_status. It adds new control flags dmarc_disable_verify and
+ dmarc_enable_forensic. The default for the dmarc_tld_file option is
+ "/etc/exim/opendmarc.tlds" and can be changed via EDITME.
+
+22. Add expansion variable $authenticated_fail_id, which is the username
+ provided to the authentication method which failed. It is available
+ for use in subsequent ACL processing (typically quit or notquit ACLs).
+
+23. New ACL modifier "udpsend" can construct a UDP packet to send to a given
+ UDP host and port.
+
+24. New ${hexquote:..string..} expansion operator converts non-printable
+ characters in the string to \xNN form.
+
+25. Experimental TPDA (Transport Post Delivery Action) function added.
+ Patch provided by Axel Rau.
+
+26. Experimental Redis lookup added. Patch provided by Warren Baker.
+
+
+Version 4.80
+------------
+
+ 1. New authenticator driver, "gsasl". Server-only (at present).
+ This is a SASL interface, licensed under GPL, which can be found at
+ http://www.gnu.org/software/gsasl/.
+ This system does not provide sources of data for authentication, so
+ 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.gnutls.org/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.
+
+17. SSLv2 now disabled by default in OpenSSL. (Never supported by GnuTLS).
+ Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
+ install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
+
+
+Version 4.77
git://git.exim.org / exim.git / blobdiff