The word &"set"& at the start of a line, followed by a single space,
is recognised specially as defining a value for a variable.
+.new
+.cindex "tainted data" "expansion testing"
+If the sequence &",t"& is inserted before the space,
+the value is marked as tainted.
+.wen
The syntax is otherwise the same as the ACL modifier &"set ="&.
.cmdopt -bem <&'filename'&>
${lookup pgsql,servers=master/db/name/pw {UPDATE ...} }
.endd
-An older syntax places the servers specification before the query,
+.new
+A now-deprecated syntax places the servers specification before the query,
semicolon separated:
.code
${lookup mysql{servers=master; UPDATE ...} }
.endd
-The new version avoids potential issues with tainted
-arguments in the query, for explicit expansion.
+The new version avoids issues with tainted
+arguments explicitly expanded as part of the query.
+The entire string within the braces becomes tainted,
+including the server sepcification - which is not permissible.
+If the older sytax is used, a warning message will be logged.
+This syntax will be removed in a future release.
+.wen
+
&*Note*&: server specifications in list-style lookups are still problematic.
.section "Expansion of lists" "SECTlistexpand"
.cindex "expansion" "of lists"
Each list is expanded as a single string before it is used.
+.cindex "tainted data" tracking
+&*Note*&: As a result, if any componend was tainted then the
+entire result string becomes tainted.
&'Exception: the router headers_remove option, where list-item
splitting is done before string-expansion.'&
below in section &<<SECTexpansionitems>>& onwards. Backslash is used as an
escape character, as described in the following section.
+.cindex "tainted data" tracking
+If any porttion of the result string is tainted, the entire result is.
+
Whether a string is expanded depends upon the context. Usually this is solely
dependent upon the option for which a value is sought; in this documentation,
options for which string expansion is performed are marked with † after
.row &%dsn_advertise_hosts%& "advertise DSN extensions to these hosts"
.row &%ignore_fromline_hosts%& "allow &""From ""& from these hosts"
.row &%ignore_fromline_local%& "allow &""From ""& from local SMTP"
+.row &%limits_advertise_hosts%& "advertise LIMITS to these hosts"
.row &%pipelining_advertise_hosts%& "advertise pipelining to these hosts"
.row &%pipelining_connect_advertise_hosts%& "advertise pipelining to these hosts"
.row &%prdr_enable%& "advertise PRDR to all hosts"
+.new
+.option limits_advertise_hosts main "host list&!!" *
+.cindex LIMITS "suppressing advertising"
+.cindex "ESMTP extensions" LIMITS
+This option can be used to suppress the advertisement of the SMTP
+LIMITS extension (RFC 9422) to specific hosts.
+If permitted, Exim as a servier will advertise in the EHLO response
+the limit for RCPT commands set by the &%recipients_max%& option (if it is set)
+and the limit for MAIL commands set by the &%smtp_accept_max_per_connection%&
+option.
+,wen
+
.option local_from_check main boolean true
.cindex "&'Sender:'& header line" "disabling addition of"
.cindex "&'From:'& header line" "disabling checking of"
option was not set.
-.option recipients_max main integer 50000
+.option recipients_max main integer&!! 50000
.cindex "limit" "number of recipients"
.cindex "recipient" "maximum number"
-If this option is set greater than zero, it specifies the maximum number of
+If the value resulting from expanding this option
+is set greater than zero, it specifies the maximum number of
original recipients for any message. Additional recipients that are generated
by aliasing or forwarding do not count. SMTP messages get a 452 response for
all recipients over the limit; earlier recipients are delivered as normal.
Non-SMTP messages with too many recipients are failed, and no deliveries are
done.
+.new
+For SMTP message the expansion is done after the connection is
+accepted (but before any SMTP conversation) and may depend on
+the IP addresses and port numbers of the connection.
+&*Note*&: If an expansion is used for the option,
+care should be taken that a resonable value results for
+non-SMTP messages.
+.wen
+
.cindex "RCPT" "maximum number of incoming"
&*Note*&: The RFCs specify that an SMTP server should accept at least 100
RCPT commands in a single message.
For testing purposes, this value can be overridden by the &%-oB%& command line
option.
+.new
+.cindex "ESMTP extensions" LIMITS
+If the peer advertises a LIMITS extension with a MAILMAX value,
+and either TLSS is in use or was not advertised,
+that value also constrains the result of this option.
+.wen
+
.option dane_require_tls_ciphers smtp string&!! unset
.cindex "TLS" "requiring specific ciphers for DANE"
so can cause parallel connections to the same host if &%remote_max_parallel%&
permits this.
+.new
+.cindex "ESMTP extensions" LIMITS
+If the peer advertises a LIMITS extension with a RCPTMAX value,
+and either TLSS is in use or was not advertised,
+that value also constrains the result of this option
+and no parallel connections will be caused on meeting the RCPTMAX limit.
+.wen
+
.option message_linelength_limit smtp integer 998
.cindex "line length" limit
only messages having the domain used for the DANE TLSA lookup are
sent on the connection.
+.new
+.cindex "ESMTP extensions" LIMITS
+If the peer advertises a LIMITS extension with a RCPTDOMAINMAX value,
+and either TLSS is in use or was not advertised,
+this option is regarded as being false.
+.wen
+
+
.option port smtp string&!! "see below"
.cindex "port" "sending TCP/IP"
.cindex "TCP/IP" "setting outgoing port"
The &%acl_smtp_dkim%& ACL is available only when Exim is compiled with DKIM support
enabled (which is the default).
+If, for a specific message, an ACL control
+&*dkim_disable_verify*&
+has been set, this &%acl_smtp_dkim%& ACL is not called.
+
The ACL test specified by &%acl_smtp_dkim%& happens after a message has been
received, and is executed for each DKIM signature found in a message. If not
otherwise specified, the default action is to accept.
.section "Format of an ACL" "SECID199"
.cindex "&ACL;" "format of"
.cindex "&ACL;" "verbs, definition of"
-An individual ACL consists of a number of statements. Each statement starts
+An individual ACL definition consists of a number of statements.
+Each statement starts
with a verb, optionally followed by a number of conditions and &"modifiers"&.
Modifiers can change the way the verb operates, define error and log messages,
set variables, insert delays, and vary the processing of accepted messages.
all the conditions make sense at every testing point. For example, you cannot
test a sender address in the ACL that is run for a VRFY command.
+The definition of an ACL ends where another starts,
+or a different configuration section starts.
+
.section "ACL verbs" "SECID200"
The ACL verbs are as follows:
.olist
Signing outgoing messages: This function is implemented in the SMTP transport.
It can co-exist with all other Exim features
-(including transport filters)
-except cutthrough delivery.
+(including transport filters) except cutthrough delivery.
+.new
+However, signing options may not depend on headers modified by
+routers, the transport or a transport filter.
+.wen
.next
Verifying signatures in incoming messages: This is implemented by an additional
ACL (acl_smtp_dkim), which can be called several times per message, with
git://git.exim.org / exim.git / blobdiff