. Update the Copyright year (only) when changing content.
. /////////////////////////////////////////////////////////////////////////////
-.set previousversion "4.80"
+.set previousversion "4.83"
.include ./local_params
.set ACL "access control lists (ACLs)"
The next two lines are concerned with &'ident'& callbacks, as defined by RFC
1413 (hence their names):
.code
-rfc1413_query_hosts = *
+rfc1413_hosts = *
rfc1413_query_timeout = 0s
.endd
These settings cause Exim to avoid ident callbacks for all incoming SMTP calls.
Thus, in the default case, as long as at least one of the DNS lookups
yields some data, the lookup succeeds.
-.new
.cindex "DNSSEC" "dns lookup"
Use of &(DNSSEC)& is controlled by a dnssec modifier.
The possible keywords are
The default is &"never"&.
See also the &$lookup_dnssec_authenticated$& variable.
-.wen
LDAP connections, rather than the SSL-on-connect &`ldaps`&.
See the &%ldap_start_tls%& option.
-.new
Starting with Exim 4.83, the initialization of LDAP with TLS is more tightly
controlled. Every part of the TLS configuration can be configured by settings in
&_exim.conf_&. Depending on the version of the client libraries installed on
running as could affect which config files it read. With Exim 4.83, these
methods become optional, only taking effect if not specifically set in
&_exim.conf_&.
-.wen
.section "LDAP quoting" "SECID68"
&`USER `& set the DN, for authenticating the LDAP bind
&`PASS `& set the password, likewise
&`REFERRALS `& set the referrals parameter
-.new
&`SERVERS `& set alternate server list for this query only
-.wen
&`SIZE `& set the limit for the number of entries returned
&`TIME `& set the maximum waiting time for a query
.endd
The TIME parameter (also a number of seconds) is passed to the server to
set a server-side limit on the time taken to complete a search.
-.new
The SERVERS parameter allows you to specify an alternate list of ldap servers
to use for an individual lookup. The global ldap_servers option provides a
default list of ldap servers, and a single lookup can specify a single ldap
different than the default list (maybe different order, maybe a completely
different set of servers), the SERVERS parameter allows you to specify this
alternate list.
-.wen
Here is an example of an LDAP query in an Exim lookup that uses some of these
values. This is a single line, folded to fit on the page:
list. The effect of each one lasts until the next, or until the end of the
list.
-.new
.section "Mixing wildcarded host names and addresses in host lists" &&&
"SECTmixwilhos"
.cindex "host list" "mixing names and addresses in"
&`+ignore_unknown`&, which was discussed in depth in the first example in
this section.
.endlist
-.wen
.section "Temporary DNS errors when looking up host information" &&&
If the ACL returns defer the result is a forced-fail. Otherwise the expansion fails.
-.new
.vitem "&*${certextract{*&<&'field'&>&*}{*&<&'certificate'&>&*}&&&
{*&<&'string2'&>&*}{*&<&'string3'&>&*}}*&"
.cindex "expansion" "extracting cerificate fields"
if so the elenment tags are omitted.
If not otherwise noted field values are presented in human-readable form.
-.wen
.vitem "&*${dlfunc{*&<&'file'&>&*}{*&<&'function'&>&*}{*&<&'arg'&>&*}&&&
{*&<&'arg'&>&*}...}*&"
{*&<&'string2'&>&*}}*&"
.cindex "expansion" "running a command"
.cindex "&%run%& expansion item"
-The command and its arguments are first expanded separately, and then the
-command is run in a separate process, but under the same uid and gid. As in
-other command executions from Exim, a shell is not used by default. If you want
+The command and its arguments are first expanded as one string. The string is
+split apart into individual arguments by spaces, and then the command is run
+in a separate process, but under the same uid and gid. As in other command
+executions from Exim, a shell is not used by default. If the command requires
a shell, you must explicitly code it.
+Since the arguments are split by spaces, when there is a variable expansion
+which has an empty result, it will cause the situation that the argument will
+simply be omitted when the program is actually executed by Exim. If the
+script/program requires a specific number of arguments and the expanded
+variable could possibly result in this empty expansion, the variable must be
+quoted. This is more difficult if the expanded variable itself could result
+in a string containing quotes, because it would interfere with the quotes
+around the command arguments. A possible guard against this is to wrap the
+variable in the &%sg%& operator to change any quote marks to some other
+character.
+
The standard input for the command exists, but is empty. The standard output
and standard error are set to the same file descriptor.
.cindex "return code" "from &%run%& expansion"
Exim filter files include an &%if%& command with its own regular expression
matching condition.
+.new
+.vitem "&$acl_arg1$&, &$acl_arg2$&, etc"
+Within an acl condition, expansion condition or expansion item
+any arguments are copied to these variables,
+any unused variables being made empty.
+.wen
+
.vitem "&$acl_c...$&"
Values can be placed in these variables by the &%set%& modifier in an ACL. They
can be given any name that starts with &$acl_c$& and is at least six characters
and can be accessed by filters, routers, and transports during subsequent
delivery.
+.new
+.vitem &$acl_narg$&
+Within an acl condition, expansion condition or expansion item
+this variable has the number of arguments.
+.wen
+
.vitem &$acl_verify_message$&
.vindex "&$acl_verify_message$&"
After an address verification has failed, this variable contains the failure
the space value is -1. See also the &%check_log_space%& option.
-.new
.vitem &$lookup_dnssec_authenticated$&
.vindex "&$lookup_dnssec_authenticated$&"
This variable is set after a DNS lookup done by
It will be empty if &(DNSSEC)& was not requested,
&"no"& if the result was not labelled as authenticated data
and &"yes"& if it was.
-.wen
.vitem &$mailstore_basename$&
.vindex "&$mailstore_basename$&"
this depends upon the TLS implementation used.
If TLS has not been negotiated, the value will be 0.
-.new
.vitem &$tls_in_ourcert$&
.vindex "&$tls_in_ourcert$&"
This variable refers to the certificate presented to the peer of an
It is only useful as the argument of a
&%certextract%& expansion item, &%md5%& or &%sha1%& operator,
or a &%def%& condition.
-.wen
-.new
.vitem &$tls_in_peercert$&
.vindex "&$tls_in_peercert$&"
This variable refers to the certificate presented by the peer of an
It is only useful as the argument of a
&%certextract%& expansion item, &%md5%& or &%sha1%& operator,
or a &%def%& condition.
-.wen
-.new
.vitem &$tls_out_ourcert$&
.vindex "&$tls_out_ourcert$&"
This variable refers to the certificate presented to the peer of an
outbound connection. It is only useful as the argument of a
&%certextract%& expansion item, &%md5%& or &%sha1%& operator,
or a &%def%& condition.
-.wen
-.new
.vitem &$tls_out_peercert$&
.vindex "&$tls_out_peercert$&"
This variable refers to the certificate presented by the peer of an
outbound connection. It is only useful as the argument of a
&%certextract%& expansion item, &%md5%& or &%sha1%& operator,
or a &%def%& condition.
-.wen
.vitem &$tls_in_certificate_verified$&
.vindex "&$tls_in_certificate_verified$&"
-.new
.option dnssec_request_domains dnslookup "domain list&!!" unset
.cindex "MX record" "security"
.cindex "DNSSEC" "MX lookup"
DNS lookups for domains matching &%dnssec_request_domains%& will be done with
the dnssec request bit set.
This applies to all of the SRV, MX A6, AAAA, A lookup sequence.
-.wen
-.new
.option dnssec_require_domains dnslookup "domain list&!!" unset
.cindex "MX record" "security"
.cindex "DNSSEC" "MX lookup"
the dnssec request bit set. Any returns not having the Authenticated Data bit
(AD bit) set wil be ignored and logged as a host-lookup failure.
This applies to all of the SRV, MX A6, AAAA, A lookup sequence.
-.wen
details.
-.new
.option dnssec_request_domains smtp "domain list&!!" unset
.cindex "MX record" "security"
.cindex "DNSSEC" "MX lookup"
DNS lookups for domains matching &%dnssec_request_domains%& will be done with
the dnssec request bit set.
This applies to all of the SRV, MX A6, AAAA, A lookup sequence.
-.wen
-.new
.option dnssec_require_domains smtp "domain list&!!" unset
.cindex "MX record" "security"
.cindex "DNSSEC" "MX lookup"
the dnssec request bit set. Any returns not having the Authenticated Data bit
(AD bit) set wil be ignored and logged as a host-lookup failure.
This applies to all of the SRV, MX A6, AAAA, A lookup sequence.
-.wen
send email. Details of how this works are given in section
&<<SECTverifyCSA>>&.
-.new
.vitem &*verify&~=&~header_names_ascii*&
.cindex "&%verify%& ACL condition"
.cindex "&ACL;" "verifying header names only ASCII"
Exim itself will handle headers with non-ASCII characters, but it can cause
problems for downstream applications, so this option will allow their
detection and rejection in the DATA ACL's.
-.wen
.vitem &*verify&~=&~header_sender/*&<&'options'&>
.cindex "&%verify%& ACL condition"
.code
exim -bp
.endd
-.new
The &*-C*& option is used to specify an alternate &_exim.conf_& which might
contain alternate exim configuration the queue management might be using.
-.wen
to obtain a queue listing, and then greps the output to select messages
that match given criteria. The following selection options are available: