.cindex "environment"
If &%environment%& is given as an argument, the set of environment
-variables is output, line by line. Using the &%-n%& flag supresses the value of the
+variables is output, line by line. Using the &%-n%& flag suppresses the value of the
variables.
.cindex "options" "macro &-- extracting"
This is an almost obsolete form of explicit email routing. If you do not know
anything about it, you can safely ignore this topic.
-The last two settings in the main part of the default configuration are
+The next two settings in the main part of the default configuration are
concerned with messages that have been &"frozen"& on Exim's queue. When a
message is frozen, Exim no longer continues to try to deliver it. Freezing
occurs when a bounce message encounters a permanent failure because the sender
after a week. In this configuration, the first setting ensures that no failing
bounce message ever lasts a week.
+Exim queues it's messages in a spool directory. If you expect to have
+large queues, you may consider using this option. It splits the spool
+directory into subdirectories to avoid file system degradation from
+many files in a single directory, resulting in better performance.
+Manual manipulation of queued messages becomes more complex (though fortunately
+not often needed).
+.code
+# split_spool_directory = true
+.endd
+
+In an ideal world everybody follows the standards. For non-ASCII
+messages RFC 2047 is a standard, allowing a maximum line length of 76
+characters. Exim adheres that standard and won't process messages which
+violate this standard. (Even ${rfc2047:...} expansions will fail.)
+In particular, the Exim maintainers have had multiple reports of
+problems from Russian administrators of issues until they disable this
+check, because of some popular, yet buggy, mail composition software.
+.code
+# check_rfc2047_length = false
+.endd
+
+If you need to be strictly RFC compliant you may wish to disable the
+8BITMIME advertisement. Use this, if you exchange mails with systems
+that are not 8-bit clean.
+.code
+# accept_8bitmime = false
+.endd
+
+Libraries you use may depend on specific environment settings. This
+imposes a security risk (e.g. PATH). There are two lists:
+&%keep_environment%& for the variables to import as they are, and
+&%add_environment%& for variables we want to set to a fixed value.
+Note that TZ is handled separately, by the $%timezone%$ runtime
+option and by the TIMEZONE_DEFAULT buildtime option.
+.code
+# keep_environment = ^LDAP
+# add_environment = PATH=/usr/bin::/bin
+.endd
.section "ACL configuration" "SECID54"
.vitem "&*${env{*&<&'key'&>&*}{*&<&'string1'&>&*}{*&<&'string2'&>&*}}*&"
.cindex "expansion" "extracting value from environment"
-.cindex "environment" "value from"
+.cindex "environment" "values from"
The key is first expanded separately, and leading and trailing white space
removed.
This is then searched for as a name in the environment.
If {<&'string1'&>} is omitted the search result is substituted on
search success.
+The environment is adjusted by the &%keep_environment%& and
+&%add_environment%& main section options.
+
.vitem "&*${extract{*&<&'key'&>&*}{*&<&'string1'&>&*}{*&<&'string2'&>&*}&&&
{*&<&'string3'&>&*}}*&"
by a setting on the transport itself.
When running a filter test via the &%-bf%& option, &$home$& is set to the value
-of the environment variable HOME.
+of the environment variable HOME, which is subject to the
+&%keep_environment%& and &%add_environment%& main config options.
.vitem &$host$&
.vindex "&$host$&"
This variable is set to the remote host's TCP port whenever &$host$& is set
for an outbound connection.
+.vitem &$initial_cwd$&
+.vindex "&$initial_cwd$&
+This variable contains the full path name of the initial working
+directory of the current Exim process. This may differ from the current
+working directory, as Exim changes this to "/" during early startup, and
+to &$spool_directory$& later.
.vitem &$inode$&
.vindex "&$inode$&"
.new
.option add_environment main "string list" empty
-.cindex "environment" "inherited"
+.cindex "environment" "set values"
This option allows to set individual environment variables that the
currently linked libraries and programs in child processes use. The
default list is empty,
.new
.option keep_environment main "string list" unset
-.cindex "environment" "inherited"
+.cindex "environment" "values from"
This option contains a string list of environment variables to keep.
You have to trust these variables or you have to be sure that
these variables do not impose any security risk. Keep in mind that
.option timezone main string unset
.cindex "timezone, setting"
+.cindex "environment" "values from"
The value of &%timezone%& is used to set the environment variable TZ while
running Exim (if it is different on entry). This ensures that all timestamps
created by Exim are in the required timezone. If you want all your timestamps
Curve names of the form &'prime256v1'& are accepted.
For even more-recent library versions, names of the form &'P-512'&
are also accepted, plus the special value &'auto'&
-which tell the library to choose.
+which tells the library to choose.
If the option is set to an empty string, no EC curves will be enabled.
An attempt to set this option for any recipient but the first
for a mail will be quietly ignored.
-If a recipient-verify callout connection is subsequently
+If a recipient-verify callout
+.new
+(with use_sender)
+.wen
+connection is subsequently
requested in the same ACL it is held open and used for
any subsequent recipients and the data,
otherwise one is made after the initial RCPT ACL completes.
projects / exim.git / blobdiff