An &"easier"& discussion of Exim which provides more in-depth explanatory,
introductory, and tutorial material can be found in a book entitled &'The Exim
SMTP Mail Server'& (second edition, 2007), published by UIT Cambridge
-(&url(http://www.uit.co.uk/exim-book/)).
+(&url(https://www.uit.co.uk/exim-book/)).
This book also contains a chapter that gives a general introduction to SMTP and
Internet mail. Inevitably, however, the book is unlikely to be fully up-to-date
.cindex "FAQ"
As well as Exim distribution tar files, the Exim web site contains a number of
differently formatted versions of the documentation. A recent addition to the
-online information is the Exim wiki (&url(http://wiki.exim.org)),
+online information is the Exim wiki (&url(https://wiki.exim.org)),
which contains what used to be a separate FAQ, as well as various other
examples, tips, and know-how that have been contributed by Exim users.
The wiki site should always redirect to the correct place, which is currently
the Debian-specific mailing list &'pkg-exim4-users@lists.alioth.debian.org'&
via this web page:
.display
-&url(http://lists.alioth.debian.org/mailman/listinfo/pkg-exim4-users)
+&url(https://alioth-lists.debian.net/cgi-bin/mailman/listinfo/pkg-exim4-users)
.endd
Please ask Debian-specific questions on this list and not on the general Exim
lists.
.cindex "distribution" "https site"
The master distribution site for the Exim distribution is
.display
-&*https://downloads.exim.org/*&
+.url(https://downloads.exim.org/)
.endd
The service is available over HTTPS, HTTP and FTP.
We encourage people to migrate to HTTPS.
-The content served at &'https://downloads.exim.org/'& is identical to the
-content served at &'https://ftp.exim.org/pub/exim'& and
-&'ftp://ftp.exim.org/pub/exim'&.
+The content served at &url(https://downloads.exim.org/) is identical to the
+content served at &url(https://ftp.exim.org/pub/exim) and
+&url(ftp://ftp.exim.org/pub/exim).
If accessing via a hostname containing &'ftp'&, then the file references that
follow are relative to the &_exim_& directories at these sites.
version.
This code implements Dan Bernstein's Constant DataBase (cdb) spec. Information,
the spec and sample code for cdb can be obtained from
-&url(http://www.pobox.com/~djb/cdb.html). This implementation borrows
+&url(https://cr.yp.to/cdb.html). This implementation borrows
some code from Dan Bernstein's implementation (which has no license
restrictions applied to it).
.endblockquote
acknowledgment:
&"This product includes software developed by Computing Services
-at Carnegie Mellon University (&url(http://www.cmu.edu/computing/)."&
+at Carnegie Mellon University (&url(https://www.cmu.edu/computing/)."&
CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
described in more detail in chapter &<<CHAProutergeneric>>&.
.ilist
+.cindex affix "router precondition"
The &%local_part_prefix%& and &%local_part_suffix%& options can specify that
the local parts handled by the router may or must have certain prefixes and/or
suffixes. If a mandatory affix (prefix or suffix) is not present, the router is
.vindex "&$local_part_prefix$&"
.vindex "&$local_part$&"
.vindex "&$local_part_suffix$&"
+.cindex affix "router precondition"
If the &%local_parts%& option is set, the local part of the address must be in
the set of local parts that it defines. If &%local_part_prefix%& or
&%local_part_suffix%& is in use, the prefix or suffix is removed from the local
If your operating system has no
PCRE support then you will need to obtain and build the current PCRE
from &url(ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/).
-More information on PCRE is available at &url(http://www.pcre.org/).
+More information on PCRE is available at &url(https://www.pcre.org/).
.section "DBM libraries" "SECTdb"
.cindex "DBM libraries" "discussion of"
.next
To complicate things further, there are several very different versions of the
Berkeley DB package. Version 1.85 was stable for a very long time, releases
-2.&'x'& and 3.&'x'& were current for a while, but the latest versions are now
-numbered 4.&'x'&. Maintenance of some of the earlier releases has ceased. All
-versions of Berkeley DB can be obtained from
-&url(http://www.sleepycat.com/).
+2.&'x'& and 3.&'x'& were current for a while, but the latest versions when Exim last revamped support were numbered 4.&'x'&.
+Maintenance of some of the earlier releases has ceased. All versions of
+Berkeley DB could be obtained from
+&url(http://www.sleepycat.com/), which is now a redirect to their new owner's
+page with far newer versions listed.
+It is probably wise to plan to move your storage configurations away from
+Berkeley DB format, as today there are smaller and simpler alternatives more
+suited to Exim's usage model.
.next
.cindex "&'tdb'& DBM library"
Yet another DBM library, called &'tdb'&, is available from
-&url(http://download.sourceforge.net/tdb). It has its own interface, and also
+&url(https://sourceforge.net/projects/tdb/files/). It has its own interface, and also
operates on a single file.
.endlist
However, some of the operating systems that supply &[iconv()]& do not support
very many conversions. The GNU &%libiconv%& library (available from
-&url(http://www.gnu.org/software/libiconv/)) can be installed on such
+&url(https://www.gnu.org/software/libiconv/)) can be installed on such
systems to remedy this deficiency, as well as on systems that do not supply
&[iconv()]& at all. After installing &%libiconv%&, you should add
.code
.vitem &%-bfp%&&~<&'prefix'&>
.oindex "&%-bfp%&"
+.cindex affix "filter testing"
This sets the prefix of the local part of the recipient address when a filter
file is being tested by means of the &%-bf%& option. The default is an empty
prefix.
.vitem &%-bfs%&&~<&'suffix'&>
.oindex "&%-bfs%&"
+.cindex affix "filter testing"
This sets the suffix of the local part of the recipient address when a filter
file is being tested by means of the &%-bf%& option. The default is an empty
suffix.
Features such as authentication and encryption, where the client input is not
plain text, cannot easily be tested with &%-bh%&. Instead, you should use a
specialized SMTP test program such as
-&url(http://jetmore.org/john/code/#swaks,swaks).
+&url(https://www.jetmore.org/john/code/swaks/,swaks).
.vitem &%-bhc%&&~<&'IP&~address'&>
.oindex "&%-bhc%&"
many Perl reference books, and also in
Jeffrey Friedl's &'Mastering Regular Expressions'&, which is published by
O'Reilly (see &url(http://www.oreilly.com/catalog/regex2/)).
+. --- the http: URL here redirects to another page with the ISBN in the URL
+. --- where trying to use https: just redirects back to http:, so sticking
+. --- to the old URL for now. 2018-09-07.
The documentation for the syntax and semantics of the regular expressions that
are supported by PCRE is included in the PCRE distribution, and no further
string without a terminating binary zero. The cdb format is designed for
indexed files that are read frequently and never updated, except by total
re-creation. As such, it is particularly suitable for large files containing
-aliases or other indexed data referenced by an MTA. Information about cdb can
-be found in several places:
+aliases or other indexed data referenced by an MTA. Information about cdb and
+tools for building the files can be found in several places:
.display
-&url(http://www.pobox.com/~djb/cdb.html)
-&url(ftp://ftp.corpit.ru/pub/tinycdb/)
-&url(http://packages.debian.org/stable/utils/freecdb.html)
+&url(https://cr.yp.to/cdb.html)
+&url(http://www.corpit.ru/mjt/tinycdb.html)
+&url(https://packages.debian.org/stable/utils/freecdb)
+&url(https://github.com/philpennock/cdbtools) (in Go)
.endd
+. --- 2018-09-07: corpit.ru http:-only
A cdb distribution is not needed in order to build Exim with cdb support,
because the code for reading cdb files is included directly in Exim itself.
However, no means of building or testing cdb files is provided with Exim, so
.next
.cindex "whoson lookup type"
.cindex "lookup" "whoson"
+. --- still http:-only, 2018-09-07
&(whoson)&: &'Whoson'& (&url(http://whoson.sourceforge.net)) is a protocol that
allows a server to check whether a particular (dynamically allocated) IP
address is currently allocated to a known (trusted) user and, optionally, to
.cindex "expansion" "PAM authentication test"
.cindex "&%pam%& expansion condition"
&'Pluggable Authentication Modules'&
-(&url(http://www.kernel.org/pub/linux/libs/pam/)) are a facility that is
+(&url(https://mirrors.edge.kernel.org/pub/linux/libs/pam/)) are a facility that is
available in the latest releases of Solaris and in some GNU/Linux
distributions. The Exim support, which is intended for use in conjunction with
the SMTP AUTH command, is available only if Exim is compiled with
In some operating systems, PAM authentication can be done only from a process
running as root. Since Exim is running as the Exim user when receiving
messages, this means that PAM cannot be used directly in those systems.
-A patched version of the &'pam_unix'& module that comes with the
-Linux PAM package is available from &url(http://www.e-admin.de/pam_exim/).
-The patched module allows one special uid/gid combination, in addition to root,
-to authenticate. If you build the patched module to allow the Exim user and
-group, PAM can then be used from an Exim authenticator.
+. --- 2018-09-07: the pam_exim modified variant has gone, removed claims re using Exim via that
.vitem &*pwcheck&~{*&<&'string1'&>&*:*&<&'string2'&>&*}*&
.vindex "&$local_part_prefix$&"
.vindex "&$local_part_suffix$&"
+.cindex affix variables
If a local part prefix or suffix has been recognized, it is not included in the
value of &$local_part$& during routing and subsequent delivery. The values of
any prefix or suffix are in &$local_part_prefix$& and
.vitem &$local_part_prefix$&
.vindex "&$local_part_prefix$&"
+.cindex affix variables
When an address is being routed or delivered, and a
specific prefix for the local part was recognized, it is available in this
variable, having been removed from &$local_part$&.
It now defaults to true.
A more detailed analysis of the issues is provided by Dan Bernstein:
.display
-&url(http://cr.yp.to/smtp/8bitmime.html)
+&url(https://cr.yp.to/smtp/8bitmime.html)
.endd
To log received 8BITMIME status use
the p11-kit configuration files in &_/etc/pkcs11/modules/_&.
See
-&url(http://www.gnutls.org/manual/gnutls.html#Smart-cards-and-HSMs)
+&url(https://www.gnutls.org/manual/gnutls.html#Smart-cards-and-HSMs)
for documentation.
.option local_part_prefix routers&!? "string list" unset
+.cindex affix "router precondition"
.cindex "router" "prefix for local part"
.cindex "prefix" "for local part, used in router"
If this option is set, the router is skipped unless the local part starts with
.scindex IIDcyrauth2 "authenticators" "&(cyrus_sasl)&"
.cindex "Cyrus" "SASL library"
.cindex "Kerberos"
-The code for this authenticator was provided by Matthew Byng-Maddick of A L
-Digital Ltd (&url(http://www.aldigital.co.uk)).
+The code for this authenticator was provided by Matthew Byng-Maddick while
+at A L Digital Ltd.
The &(cyrus_sasl)& authenticator provides server support for the Cyrus SASL
library implementation of the RFC 2222 (&"Simple Authentication and Security
Password Authentication'& mechanism,
which is also sometimes known as NTLM (NT LanMan). The code for client side of
this authenticator was contributed by Marc Prud'hommeaux, and much of it is
-taken from the Samba project (&url(http://www.samba.org)). The code for the
+taken from the Samba project (&url(https://www.samba.org/)). The code for the
server side was subsequently contributed by Tom Kistner. The mechanism works as
follows:
Documentation of the strings accepted may be found in the GnuTLS manual, under
"Priority strings". This is online as
-&url(http://www.gnutls.org/manual/html_node/Priority-Strings.html),
+&url(https://www.gnutls.org/manual/html_node/Priority-Strings.html),
but beware that this relates to GnuTLS 3, which may be newer than the version
installed on your system. If you are using GnuTLS 3,
then the example code
-&url(http://www.gnutls.org/manual/gnutls.html#Listing-the-ciphersuites-in-a-priority-string)
+&url(https://www.gnutls.org/manual/gnutls.html#Listing-the-ciphersuites-in-a-priority-string)
on that site can be used to test a given string.
For example:
.section "Certificates and all that" "SECTcerandall"
.cindex "certificate" "references to discussion"
In order to understand fully how TLS works, you need to know about
-certificates, certificate signing, and certificate authorities. This is not the
-place to give a tutorial, especially as I do not know very much about it
-myself. Some helpful introduction can be found in the FAQ for the SSL addition
-to Apache, currently at
+certificates, certificate signing, and certificate authorities.
+This is a large topic and an introductory guide is unsuitable for the Exim
+reference manual, so instead we provide pointers to existing documentation.
+
+The Apache web-server was for a long time the canonical guide, so their
+documentation is a good place to start; their SSL module's Introduction
+document is currently at
.display
-&url(http://www.modssl.org/docs/2.7/ssl_faq.html#ToC24)
+.url(https://httpd.apache.org/docs/current/ssl/ssl_intro.html)
.endd
-Other parts of the &'modssl'& documentation are also helpful, and have
-links to further files.
-Eric Rescorla's book, &'SSL and TLS'&, published by Addison-Wesley (ISBN
-0-201-61598-3), contains both introductory and more in-depth descriptions.
-Some sample programs taken from the book are available from
+and their FAQ is at
.display
-&url(http://www.rtfm.com/openssl-examples/)
+&url(https://httpd.apache.org/docs/current/ssl/ssl_faq.html)
.endd
+Eric Rescorla's book, &'SSL and TLS'&, published by Addison-Wesley (ISBN
+0-201-61598-3) in 2001, contains both introductory and more in-depth
+descriptions.
+More recently Ivan Ristić's book &'Bulletproof SSL and TLS'&,
+published by Feisty Duck (ISBN 978-1907117046) in 2013 is good.
+Ivan is the author of the popular TLS testing tools at
+&url(https://www.ssllabs.com/).
+
.section "Certificate chains" "SECID186"
The file named by &%tls_certificate%& may contain more than one
For information on creating self-signed CA certificates and using them to sign
user certificates, see the &'General implementation overview'& chapter of the
Open-source PKI book, available online at
-&url(http://ospkibook.sourceforge.net/).
+&url(https://sourceforge.net/projects/ospkibook/).
.ecindex IIDencsmtp1
.ecindex IIDencsmtp2
Exim does not share information between multiple incoming
connections (but your local name server cache should be active).
+There are a number of DNS lists to choose from, some commercial, some free,
+or free for small deployments. An overview can be found at
+&url(https://en.wikipedia.org/wiki/Comparison_of_DNS_blacklists).
+
.section "Specifying the IP address for a DNS list lookup" "SECID201"
.section "DNS lists keyed on domain names" "SECID202"
.cindex "DNS list" "keyed by domain name"
There are some lists that are keyed on domain names rather than inverted IP
-addresses (see for example the &'domain based zones'& link at
-&url(http://www.rfc-ignorant.org/)). No reversing of components is used
+addresses. No reversing of components is used
with these lists. You can change the name that is looked up in a DNS list by
listing it after the domain name, introduced by a slash. For example,
.code
.vitem &%aveserver%&
.cindex "virus scanners" "Kaspersky"
This is the scanner daemon of Kaspersky Version 5. You can get a trial version
-at &url(http://www.kaspersky.com). This scanner type takes one option,
+at &url(https://www.kaspersky.com/). This scanner type takes one option,
which is the path to the daemon's UNIX socket. The default is shown in this
example:
.code
.vitem &%clamd%&
.cindex "virus scanners" "clamd"
This daemon-type scanner is GPL and free. You can get it at
-&url(http://www.clamav.net/). Some older versions of clamd do not seem to
+&url(https://www.clamav.net/). Some older versions of clamd do not seem to
unpack MIME containers, so it used to be recommended to unpack MIME attachments
in the MIME ACL. This is no longer believed to be necessary.
.endd
.vitem &%drweb%&
.cindex "virus scanners" "DrWeb"
-The DrWeb daemon scanner (&url(http://www.sald.com/)) interface
+The DrWeb daemon scanner (&url(https://www.sald.ru/)) interface
takes one option,
either a full path to a UNIX socket,
or host and port specifiers separated by white space.
.vitem &%fsecure%&
.cindex "virus scanners" "F-Secure"
-The F-Secure daemon scanner (&url(http://www.f-secure.com)) takes one
+The F-Secure daemon scanner (&url(https://www.f-secure.com/)) takes one
argument which is the path to a UNIX socket. For example:
.code
av_scanner = fsecure:/path/to/.fsav
.vitem &%mksd%&
.cindex "virus scanners" "mksd"
-This is a daemon type scanner that is aimed mainly at Polish users, though some
-parts of documentation are now available in English. You can get it at
-&url(http://linux.mks.com.pl/). The only option for this scanner type is
+This was a daemon type scanner that is aimed mainly at Polish users,
+though some documentation was available in English.
+The history can be shown at &url(https://en.wikipedia.org/wiki/Mks_vir)
+and this appears to be a candidate for removal from Exim, unless
+we are informed of other virus scanners which use the same protocol
+to integrate.
+The only option for this scanner type is
the maximum number of processes used simultaneously to scan the attachments,
provided that mksd has
been run with at least the same number of child processes. For example:
.vitem &%sophie%&
.cindex "virus scanners" "Sophos and Sophie"
Sophie is a daemon that uses Sophos' &%libsavi%& library to scan for viruses.
-You can get Sophie at &url(http://www.clanfield.info/sophie/). The only option
+You can get Sophie at &url(http://sophie.sourceforge.net/). The only option
for this scanner type is the path to the UNIX socket that Sophie uses for
client communication. For example:
.code
For more information about installation and configuration of SpamAssassin or
Rspamd refer to their respective websites at
-&url(http://spamassassin.apache.org) and &url(http://www.rspamd.com)
+&url(https://spamassassin.apache.org/) and &url(https://www.rspamd.com/)
SpamAssassin can be installed with CPAN by running:
.code
.cindex "VERP"
.cindex "Variable Envelope Return Paths"
.cindex "envelope sender"
-Variable Envelope Return Paths &-- see &url(http://cr.yp.to/proto/verp.txt) &--
+Variable Envelope Return Paths &-- see &url(https://cr.yp.to/proto/verp.txt) &--
are a way of helping mailing list administrators discover which subscription
address is the cause of a particular delivery failure. The idea is to encode
the original recipient address in the outgoing envelope sender address, so that
Another utility that might be of use to sites with many MTAs is Tom Kistner's
&'exilog'&. It provides log visualizations across multiple Exim servers. See
-&url(http://duncanthrax.net/exilog/) for details.
+&url(https://duncanthrax.net/exilog/) for details.
.cindex "&'eximstats'&"
A Perl script called &'eximstats'& is provided for extracting statistical
information from log files. The output is either plain text, or HTML.
-Exim log files are also supported by the &'Lire'& system produced by the
-LogReport Foundation &url(http://www.logreport.org).
+. --- 2018-09-07: LogReport's Lire appears to be dead; website is a Yahoo Japan
+. --- 404 error and everything else points to that.
The &'eximstats'& script has been hacked about quite a bit over time. The
latest version is the result of some extensive revision by Steve Campbell. A
SPF is a mechanism whereby a domain may assert which IP addresses may transmit
messages with its domain in the envelope from, documented by RFC 7208.
For more information on SPF see &url(http://www.openspf.org).
+. --- 2018-09-07: still not https
Messages sent by a system not authorised will fail checking of such assertions.
This includes retransmissions done by traditional forwarders.
SPF verification support is built into Exim if SUPPORT_SPF=yes is set in
&_Local/Makefile_&. The support uses the &_libspf2_& library
-&url(http://www.libspf2.org/).
+&url(https://www.libspf2.org/).
There is no Exim involvement in the transmission of messages;
publishing certain DNS records is all that is required.
capability.
Refer to &url(http://www.openspf.org/FAQ/Best_guess_record)
for a description of what it means.
+. --- 2018-09-07: still not https:
To access this feature, simply use the spf_guess condition in place
of the spf one. For example:
To include this support, include &"SUPPORT_PROXY=yes"&
in Local/Makefile.
-It was built on specifications from:
-(&url(http://haproxy.1wt.eu/download/1.5/doc/proxy-protocol.txt)).
-That URL was revised in May 2014 to version 2 spec:
-(&url(http://git.1wt.eu/web?p=haproxy.git;a=commitdiff;h=afb768340c9d7e50d8e)).
+It was built on the HAProxy specification, found at
+&url(https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt).
The purpose of this facility is so that an application load balancer,
such as HAProxy, can sit in front of several Exim servers
projects / exim.git / blobdiff