<!DOCTYPE html PUBLIC "XSLT-compat"> <html lang="en-GB"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <link rel="stylesheet" type="text/css" href="../../../../common.css"> <meta name="author" content="The Exim Project. <http://www.exim.org/>"> <meta name="copyright" content="Copyright ©2010 The Exim Project. All rights reserved"> <meta name="description" content="Exim is a message transfer agent (MTA) developed at the University of Cambridge for use on Unix systems connected to the Internet."> <meta name="keywords" content="exim,smtp,mta,email"> <meta name="robots" content="noodp,noydir,index,follow"> <meta name="viewport" content="width=device-width"> <title>4. Building and installing Exim</title> <link rel="stylesheet" type="text/css" href="../../../../doc/chapter.css"> <link rel="canonical" href="http://www.exim.org/exim-html-current/doc/html/spec_html/ch04.html"> </head> <body> <h1 id="header"><a href="../../../..">Exim Internet Mailer</a></h1> <div id="outer"> <ul id="nav_flow" class="nav"> <li><a href="../../../../index.html">Home</a></li> <li><a href="../../../../mirrors.html">Download</a></li> <li><a href="../../../../docs.html">Documentation</a></li> <li><a href="../../../../maillist.html">Mailing Lists</a></li> <li><a href="http://wiki.exim.org/">Wiki</a></li> <li><a href="http://www.exim.org/bugzilla/">Bugs</a></li> <li><a href="../../../../credits.html">Credits</a></li> <li class="search"><form action="http://www.google.com/search" method="get"> <span class="search_field_container"><input type="search" name="q" placeholder="Search Docs" class="search_field"></span><input type="hidden" name="hl" value="en"><input type="hidden" name="ie" value="UTF-8"><input type="hidden" name="as_qdr" value="all"><input type="hidden" name="q" value="site:www.exim.org"><input type="hidden" name="q" value="inurl:exim-html-current"> </form></li> </ul> <div id="inner"><div id="content"> <a class="previous_page" href="ch03.html"><-previous</a><a class="next_page" href="ch05.html">next-></a><div id="chapter" class="chapter"> <h2 id="CHID3" class="">Chapter 4 - Building and installing Exim</h2> <p> </p> <div class="section"> <h3 id="SECID23" class="">1. Unpacking</h3> <p> Exim is distributed as a gzipped or bzipped tar file which, when unpacked, creates a directory with the name of the current release (for example, <span class="docbook_filename">exim-4.73</span>) into which the following files are placed: </p> <table> <tr> <td> <span class="docbook_filename">ACKNOWLEDGMENTS</span> </td> <td>contains some acknowledgments</td> </tr> <tr> <td> <span class="docbook_filename">CHANGES</span> </td> <td>contains a reference to where changes are documented</td> </tr> <tr> <td> <span class="docbook_filename">LICENCE</span> </td> <td>the GNU General Public Licence</td> </tr> <tr> <td> <span class="docbook_filename">Makefile</span> </td> <td>top-level make file</td> </tr> <tr> <td> <span class="docbook_filename">NOTICE</span> </td> <td>conditions for the use of Exim</td> </tr> <tr> <td> <span class="docbook_filename">README</span> </td> <td>list of files, directories and simple build instructions</td> </tr> </table> <p> Other files whose names begin with <span class="docbook_filename">README</span> may also be present. The following subdirectories are created: </p> <table> <tr> <td> <span class="docbook_filename">Local</span> </td> <td>an empty directory for local configuration files</td> </tr> <tr> <td> <span class="docbook_filename">OS</span> </td> <td>OS-specific files</td> </tr> <tr> <td> <span class="docbook_filename">doc</span> </td> <td>documentation files</td> </tr> <tr> <td> <span class="docbook_filename">exim_monitor</span> </td> <td>source files for the Exim monitor</td> </tr> <tr> <td> <span class="docbook_filename">scripts</span> </td> <td>scripts used in the build process</td> </tr> <tr> <td> <span class="docbook_filename">src</span> </td> <td>remaining source files</td> </tr> <tr> <td> <span class="docbook_filename">util</span> </td> <td>independent utilities</td> </tr> </table> <p> The main utility programs are contained in the <span class="docbook_filename">src</span> directory, and are built with the Exim binary. The <span class="docbook_filename">util</span> directory contains a few optional scripts that may be useful to some sites. </p> </div> <div class="section"> <h3 id="SECID24" class="">2. Multiple machine architectures and operating systems</h3> <p> The building process for Exim is arranged to make it easy to build binaries for a number of different architectures and operating systems from the same set of source files. Compilation does not take place in the <span class="docbook_filename">src</span> directory. Instead, a <span class="docbook_emphasis">build directory</span> is created for each architecture and operating system. Symbolic links to the sources are installed in this directory, which is where the actual building takes place. In most cases, Exim can discover the machine architecture and operating system for itself, but the defaults can be overridden if necessary. </p> </div> <div class="section"> <h3 id="SECTpcre" class="">3. PCRE library</h3> <p> Exim no longer has an embedded PCRE library as the vast majority of modern systems include PCRE as a system library, although you may need to install the PCRE or PCRE development package for your operating system. If your system has a normal PCRE installation the Exim build process will need no further configuration. If the library or the headers are in an unusual location you will need to set the PCRE_LIBS and INCLUDE directives appropriately. If your operating system has no PCRE support then you will need to obtain and build the current PCRE from <span class="docbook_emphasis"><a href="ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/">ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/</a></span>. </p> </div> <div class="section"> <h3 id="SECTdb" class="">4. DBM libraries</h3> <p> Even if you do not use any DBM files in your configuration, Exim still needs a DBM library in order to operate, because it uses indexed files for its hints databases. Unfortunately, there are a number of DBM libraries in existence, and different operating systems often have different ones installed. </p> <p> If you are using Solaris, IRIX, one of the modern BSD systems, or a modern Linux distribution, the DBM configuration should happen automatically, and you may be able to ignore this section. Otherwise, you may have to learn more than you would like about DBM libraries from what follows. </p> <p> Licensed versions of Unix normally contain a library of DBM functions operating via the <span class="docbook_emphasis">ndbm</span> interface, and this is what Exim expects by default. Free versions of Unix seem to vary in what they contain as standard. In particular, some early versions of Linux have no default DBM library, and different distributors have chosen to bundle different libraries with their packaged versions. However, the more recent releases seem to have standardized on the Berkeley DB library. </p> <p> Different DBM libraries have different conventions for naming the files they use. When a program opens a file called <span class="docbook_filename">dbmfile</span>, there are several possibilities: </p> <ol> <li> <p> A traditional <span class="docbook_emphasis">ndbm</span> implementation, such as that supplied as part of Solaris, operates on two files called <span class="docbook_filename">dbmfile.dir</span> and <span class="docbook_filename">dbmfile.pag</span>. </p> </li> <li> <p> The GNU library, <span class="docbook_emphasis">gdbm</span>, operates on a single file. If used via its <span class="docbook_emphasis">ndbm</span> compatibility interface it makes two different hard links to it with names <span class="docbook_filename">dbmfile.dir</span> and <span class="docbook_filename">dbmfile.pag</span>, but if used via its native interface, the file name is used unmodified. </p> </li> <li> <p> The Berkeley DB package, if called via its <span class="docbook_emphasis">ndbm</span> compatibility interface, operates on a single file called <span class="docbook_filename">dbmfile.db</span>, but otherwise looks to the programmer exactly the same as the traditional <span class="docbook_emphasis">ndbm</span> implementation. </p> </li> <li> <p> If the Berkeley package is used in its native mode, it operates on a single file called <span class="docbook_filename">dbmfile</span>; the programmer’s interface is somewhat different to the traditional <span class="docbook_emphasis">ndbm</span> interface. </p> </li> <li> <p> 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.<span class="docbook_emphasis">x</span> and 3.<span class="docbook_emphasis">x</span> were current for a while, but the latest versions are now numbered 4.<span class="docbook_emphasis">x</span>. Maintenance of some of the earlier releases has ceased. All versions of Berkeley DB can be obtained from <span class="docbook_emphasis"><a href="http://www.sleepycat.com/">http://www.sleepycat.com/</a></span>. </p> </li> <li> <p> Yet another DBM library, called <span class="docbook_emphasis">tdb</span>, is available from <span class="docbook_emphasis"><a href="http://download.sourceforge.net/tdb">http://download.sourceforge.net/tdb</a></span>. It has its own interface, and also operates on a single file. </p> </li> </ol> <p> Exim and its utilities can be compiled to use any of these interfaces. In order to use any version of the Berkeley DB package in native mode, you must set USE_DB in an appropriate configuration file (typically <span class="docbook_filename">Local/Makefile</span>). For example: </p> <div class="docbook_literallayout"><pre> USE_DB=yes </pre></div> <p> Similarly, for gdbm you set USE_GDBM, and for tdb you set USE_TDB. An error is diagnosed if you set more than one of these. </p> <p> At the lowest level, the build-time configuration sets none of these options, thereby assuming an interface of type (1). However, some operating system configuration files (for example, those for the BSD operating systems and Linux) assume type (4) by setting USE_DB as their default, and the configuration files for Cygwin set USE_GDBM. Anything you set in <span class="docbook_filename">Local/Makefile</span>, however, overrides these system defaults. </p> <p> As well as setting USE_DB, USE_GDBM, or USE_TDB, it may also be necessary to set DBMLIB, to cause inclusion of the appropriate library, as in one of these lines: </p> <div class="docbook_literallayout"><pre> DBMLIB = -ldb DBMLIB = -ltdb </pre></div> <p> Settings like that will work if the DBM library is installed in the standard place. Sometimes it is not, and the library’s header file may also not be in the default path. You may need to set INCLUDE to specify where the header file is, and to specify the path to the library more fully in DBMLIB, as in this example: </p> <div class="docbook_literallayout"><pre> INCLUDE=-I/usr/local/include/db-4.1 DBMLIB=/usr/local/lib/db-4.1/libdb.a </pre></div> <p> There is further detailed discussion about the various DBM libraries in the file <span class="docbook_filename">doc/dbm.discuss.txt</span> in the Exim distribution. </p> </div> <div class="section"> <h3 id="SECID25" class="">5. Pre-building configuration</h3> <p> Before building Exim, a local configuration file that specifies options independent of any operating system has to be created with the name <span class="docbook_filename">Local/Makefile</span>. A template for this file is supplied as the file <span class="docbook_filename">src/EDITME</span>, and it contains full descriptions of all the option settings therein. These descriptions are therefore not repeated here. If you are building Exim for the first time, the simplest thing to do is to copy <span class="docbook_filename">src/EDITME</span> to <span class="docbook_filename">Local/Makefile</span>, then read it and edit it appropriately. </p> <p> There are three settings that you must supply, because Exim will not build without them. They are the location of the run time configuration file (CONFIGURE_FILE), the directory in which Exim binaries will be installed (BIN_DIRECTORY), and the identity of the Exim user (EXIM_USER and maybe EXIM_GROUP as well). The value of CONFIGURE_FILE can in fact be a colon-separated list of file names; Exim uses the first of them that exists. </p> <p> There are a few other parameters that can be specified either at build time or at run time, to enable the same binary to be used on a number of different machines. However, if the locations of Exim’s spool directory and log file directory (if not within the spool directory) are fixed, it is recommended that you specify them in <span class="docbook_filename">Local/Makefile</span> instead of at run time, so that errors detected early in Exim’s execution (such as a malformed configuration file) can be logged. </p> <p> Exim’s interfaces for calling virus and spam scanning software directly from access control lists are not compiled by default. If you want to include these facilities, you need to set </p> <div class="docbook_literallayout"><pre> WITH_CONTENT_SCAN=yes </pre></div> <p> in your <span class="docbook_filename">Local/Makefile</span>. For details of the facilities themselves, see chapter <a href="ch41.html" title="41. Content scanning at ACL time">41</a>. </p> <p> If you are going to build the Exim monitor, a similar configuration process is required. The file <span class="docbook_filename">exim_monitor/EDITME</span> must be edited appropriately for your installation and saved under the name <span class="docbook_filename">Local/eximon.conf</span>. If you are happy with the default settings described in <span class="docbook_filename">exim_monitor/EDITME</span>, <span class="docbook_filename">Local/eximon.conf</span> can be empty, but it must exist. </p> <p> This is all the configuration that is needed in straightforward cases for known operating systems. However, the building process is set up so that it is easy to override options that are set by default or by operating-system-specific configuration files, for example to change the name of the C compiler, which defaults to <span class="docbook_option">gcc</span>. See section <a href="ch04.html#SECToverride" title="4. Building and installing Exim">4.12</a> below for details of how to do this. </p> </div> <div class="section"> <h3 id="SECID26" class="">6. Support for iconv()</h3> <p> The contents of header lines in messages may be encoded according to the rules described RFC 2047. This makes it possible to transmit characters that are not in the ASCII character set, and to label them as being in a particular character set. When Exim is inspecting header lines by means of the <span class="docbook_option">$h_</span> mechanism, it decodes them, and translates them into a specified character set (default ISO-8859-1). The translation is possible only if the operating system supports the <span class="docbook_function">iconv()</span> function. </p> <p> However, some of the operating systems that supply <span class="docbook_function">iconv()</span> do not support very many conversions. The GNU <span class="docbook_option">libiconv</span> library (available from <span class="docbook_emphasis"><a href="http://www.gnu.org/software/libiconv/">http://www.gnu.org/software/libiconv/</a></span>) can be installed on such systems to remedy this deficiency, as well as on systems that do not supply <span class="docbook_function">iconv()</span> at all. After installing <span class="docbook_option">libiconv</span>, you should add </p> <div class="docbook_literallayout"><pre> HAVE_ICONV=yes </pre></div> <p> to your <span class="docbook_filename">Local/Makefile</span> and rebuild Exim. </p> </div> <div class="section"> <h3 id="SECTinctlsssl" class="">7. Including TLS/SSL encryption support</h3> <p> Exim can be built to support encrypted SMTP connections, using the STARTTLS command as per RFC 2487. It can also support legacy clients that expect to start a TLS session immediately on connection to a non-standard port (see the <span class="docbook_option">tls_on_connect_ports</span> runtime option and the <span class="docbook_option">-tls-on-connect</span> command line option). </p> <p> If you want to build Exim with TLS support, you must first install either the OpenSSL or GnuTLS library. There is no cryptographic code in Exim itself for implementing SSL. </p> <p> If OpenSSL is installed, you should set </p> <div class="docbook_literallayout"><pre> SUPPORT_TLS=yes TLS_LIBS=-lssl -lcrypto </pre></div> <p> in <span class="docbook_filename">Local/Makefile</span>. You may also need to specify the locations of the OpenSSL library and include files. For example: </p> <div class="docbook_literallayout"><pre> SUPPORT_TLS=yes TLS_LIBS=-L/usr/local/openssl/lib -lssl -lcrypto TLS_INCLUDE=-I/usr/local/openssl/include/ </pre></div> <p> If GnuTLS is installed, you should set </p> <div class="docbook_literallayout"><pre> SUPPORT_TLS=yes USE_GNUTLS=yes TLS_LIBS=-lgnutls -ltasn1 -lgcrypt </pre></div> <p> in <span class="docbook_filename">Local/Makefile</span>, and again you may need to specify the locations of the library and include files. For example: </p> <div class="docbook_literallayout"><pre> SUPPORT_TLS=yes USE_GNUTLS=yes TLS_LIBS=-L/usr/gnu/lib -lgnutls -ltasn1 -lgcrypt TLS_INCLUDE=-I/usr/gnu/include </pre></div> <p> You do not need to set TLS_INCLUDE if the relevant directory is already specified in INCLUDE. Details of how to configure Exim to make use of TLS are given in chapter <a href="ch39.html" title="39. Encrypted SMTP connections using TLS/SSL">39</a>. </p> </div> <div class="section"> <h3 id="SECID27" class="">8. Use of tcpwrappers</h3> <p class="changed"> Exim can be linked with the <span class="docbook_emphasis">tcpwrappers</span> library in order to check incoming SMTP calls using the <span class="docbook_emphasis">tcpwrappers</span> control files. This may be a convenient alternative to Exim’s own checking facilities for installations that are already making use of <span class="docbook_emphasis">tcpwrappers</span> for other purposes. To do this, you should set USE_TCP_WRAPPERS in <span class="docbook_filename">Local/Makefile</span>, arrange for the file <span class="docbook_filename">tcpd.h</span> to be available at compile time, and also ensure that the library <span class="docbook_filename">libwrap.a</span> is available at link time, typically by including <span class="docbook_option">-lwrap</span> in EXTRALIBS_EXIM. For example, if <span class="docbook_emphasis">tcpwrappers</span> is installed in <span class="docbook_filename">/usr/local</span>, you might have </p> <div class="docbook_literallayout"><pre> USE_TCP_WRAPPERS=yes CFLAGS=-O -I/usr/local/include EXTRALIBS_EXIM=-L/usr/local/lib -lwrap </pre></div> <p class="changed"> in <span class="docbook_filename">Local/Makefile</span>. The daemon name to use in the <span class="docbook_emphasis">tcpwrappers</span> control files is “exim”. For example, the line </p> <div class="docbook_literallayout"><pre> exim : LOCAL 192.168.1. .friendly.domain.example </pre></div> <p class="changed"> in your <span class="docbook_filename">/etc/hosts.allow</span> file allows connections from the local host, from the subnet 192.168.1.0/24, and from all hosts in <span class="docbook_emphasis">friendly.domain.example</span>. All other connections are denied. The daemon name used by <span class="docbook_emphasis">tcpwrappers</span> can be changed at build time by setting TCP_WRAPPERS_DAEMON_NAME in in <span class="docbook_filename">Local/Makefile</span>, or by setting tcp_wrappers_daemon_name in the configure file. Consult the <span class="docbook_emphasis">tcpwrappers</span> documentation for further details. </p> </div> <div class="section"> <h3 id="SECID28" class="">9. Including support for IPv6</h3> <p> Exim contains code for use on systems that have IPv6 support. Setting <code class="docbook_literal">HAVE_IPV6=YES</code> in <span class="docbook_filename">Local/Makefile</span> causes the IPv6 code to be included; it may also be necessary to set IPV6_INCLUDE and IPV6_LIBS on systems where the IPv6 support is not fully integrated into the normal include and library files. </p> <p> Two different types of DNS record for handling IPv6 addresses have been defined. AAAA records (analogous to A records for IPv4) are in use, and are currently seen as the mainstream. Another record type called A6 was proposed as better than AAAA because it had more flexibility. However, it was felt to be over-complex, and its status was reduced to “experimental”. It is not known if anyone is actually using A6 records. Exim has support for A6 records, but this is included only if you set <code class="docbook_literal">SUPPORT_A6=YES</code> in <span class="docbook_filename">Local/Makefile</span>. The support has not been tested for some time. </p> </div> <div class="section"> <h3 id="SECID29" class="">10. The building process</h3> <p> Once <span class="docbook_filename">Local/Makefile</span> (and <span class="docbook_filename">Local/eximon.conf</span>, if required) have been created, run <span class="docbook_emphasis">make</span> at the top level. It determines the architecture and operating system types, and creates a build directory if one does not exist. For example, on a Sun system running Solaris 8, the directory <span class="docbook_filename">build-SunOS5-5.8-sparc</span> is created. Symbolic links to relevant source files are installed in the build directory. </p> <p> <span class="docbook_emphasis">Warning</span>: The <span class="docbook_option">-j</span> (parallel) flag must not be used with <span class="docbook_emphasis">make</span>; the building process fails if it is set. </p> <p> If this is the first time <span class="docbook_emphasis">make</span> has been run, it calls a script that builds a make file inside the build directory, using the configuration files from the <span class="docbook_filename">Local</span> directory. The new make file is then passed to another instance of <span class="docbook_emphasis">make</span>. This does the real work, building a number of utility scripts, and then compiling and linking the binaries for the Exim monitor (if configured), a number of utility programs, and finally Exim itself. The command <code class="docbook_literal">make makefile</code> can be used to force a rebuild of the make file in the build directory, should this ever be necessary. </p> <p> If you have problems building Exim, check for any comments there may be in the <span class="docbook_filename">README</span> file concerning your operating system, and also take a look at the FAQ, where some common problems are covered. </p> </div> <div class="section"> <h3 id="SECID283" class="">11. Output from make</h3> <p> The output produced by the <span class="docbook_emphasis">make</span> process for compile lines is often very unreadable, because these lines can be very long. For this reason, the normal output is suppressed by default, and instead output similar to that which appears when compiling the 2.6 Linux kernel is generated: just a short line for each module that is being compiled or linked. However, it is still possible to get the full output, by calling <span class="docbook_emphasis">make</span> like this: </p> <div class="docbook_literallayout"><pre> FULLECHO='' make -e </pre></div> <p> The value of FULLECHO defaults to “@”, the flag character that suppresses command reflection in <span class="docbook_emphasis">make</span>. When you ask for the full output, it is given in addition to the short output. </p> </div> <div class="section"> <h3 id="SECToverride" class="">12. Overriding build-time options for Exim</h3> <p> The main make file that is created at the beginning of the building process consists of the concatenation of a number of files which set configuration values, followed by a fixed set of <span class="docbook_emphasis">make</span> instructions. If a value is set more than once, the last setting overrides any previous ones. This provides a convenient way of overriding defaults. The files that are concatenated are, in order: </p> <div class="docbook_literallayout"><pre> <span class="docbook_filename">OS/Makefile-Default</span> <span class="docbook_filename">OS/Makefile-</span><<span class="docbook_emphasis">ostype</span>> <span class="docbook_filename">Local/Makefile</span> <span class="docbook_filename">Local/Makefile-</span><<span class="docbook_emphasis">ostype</span>> <span class="docbook_filename">Local/Makefile-</span><<span class="docbook_emphasis">archtype</span>> <span class="docbook_filename">Local/Makefile-</span><<span class="docbook_emphasis">ostype</span>>-<<span class="docbook_emphasis">archtype</span>> <span class="docbook_filename">OS/Makefile-Base</span> </pre></div> <p> where <<span class="docbook_emphasis">ostype</span>> is the operating system type and <<span class="docbook_emphasis">archtype</span>> is the architecture type. <span class="docbook_filename">Local/Makefile</span> is required to exist, and the building process fails if it is absent. The other three <span class="docbook_filename">Local</span> files are optional, and are often not needed. </p> <p> The values used for <<span class="docbook_emphasis">ostype</span>> and <<span class="docbook_emphasis">archtype</span>> are obtained from scripts called <span class="docbook_filename">scripts/os-type</span> and <span class="docbook_filename">scripts/arch-type</span> respectively. If either of the environment variables EXIM_OSTYPE or EXIM_ARCHTYPE is set, their values are used, thereby providing a means of forcing particular settings. Otherwise, the scripts try to get values from the <span class="docbook_option">uname</span> command. If this fails, the shell variables OSTYPE and ARCHTYPE are inspected. A number of <span class="docbook_emphasis">ad hoc</span> transformations are then applied, to produce the standard names that Exim expects. You can run these scripts directly from the shell in order to find out what values are being used on your system. </p> <p> <span class="docbook_filename">OS/Makefile-Default</span> contains comments about the variables that are set therein. Some (but not all) are mentioned below. If there is something that needs changing, review the contents of this file and the contents of the make file for your operating system (<span class="docbook_filename">OS/Makefile-<ostype></span>) to see what the default values are. </p> <p> If you need to change any of the values that are set in <span class="docbook_filename">OS/Makefile-Default</span> or in <span class="docbook_filename">OS/Makefile-<ostype></span>, or to add any new definitions, you do not need to change the original files. Instead, you should make the changes by putting the new values in an appropriate <span class="docbook_filename">Local</span> file. For example, when building Exim in many releases of the Tru64-Unix (formerly Digital UNIX, formerly DEC-OSF1) operating system, it is necessary to specify that the C compiler is called <span class="docbook_emphasis">cc</span> rather than <span class="docbook_emphasis">gcc</span>. Also, the compiler must be called with the option <span class="docbook_option">-std1</span>, to make it recognize some of the features of Standard C that Exim uses. (Most other compilers recognize Standard C by default.) To do this, you should create a file called <span class="docbook_filename">Local/Makefile-OSF1</span> containing the lines </p> <div class="docbook_literallayout"><pre> CC=cc CFLAGS=-std1 </pre></div> <p> If you are compiling for just one operating system, it may be easier to put these lines directly into <span class="docbook_filename">Local/Makefile</span>. </p> <p> Keeping all your local configuration settings separate from the distributed files makes it easy to transfer them to new versions of Exim simply by copying the contents of the <span class="docbook_filename">Local</span> directory. </p> <p> Exim contains support for doing LDAP, NIS, NIS+, and other kinds of file lookup, but not all systems have these components installed, so the default is not to include the relevant code in the binary. All the different kinds of file and database lookup that Exim supports are implemented as separate code modules which are included only if the relevant compile-time options are set. In the case of LDAP, NIS, and NIS+, the settings for <span class="docbook_filename">Local/Makefile</span> are: </p> <div class="docbook_literallayout"><pre> LOOKUP_LDAP=yes LOOKUP_NIS=yes LOOKUP_NISPLUS=yes </pre></div> <p> and similar settings apply to the other lookup types. They are all listed in <span class="docbook_filename">src/EDITME</span>. In many cases the relevant include files and interface libraries need to be installed before compiling Exim. However, there are some optional lookup types (such as cdb) for which the code is entirely contained within Exim, and no external include files or libraries are required. When a lookup type is not included in the binary, attempts to configure Exim to use it cause run time configuration errors. </p> <p> Exim can be linked with an embedded Perl interpreter, allowing Perl subroutines to be called during string expansion. To enable this facility, </p> <div class="docbook_literallayout"><pre> EXIM_PERL=perl.o </pre></div> <p> must be defined in <span class="docbook_filename">Local/Makefile</span>. Details of this facility are given in chapter <a href="ch12.html" title="12. Embedded Perl">12</a>. </p> <p> The location of the X11 libraries is something that varies a lot between operating systems, and there may be different versions of X11 to cope with. Exim itself makes no use of X11, but if you are compiling the Exim monitor, the X11 libraries must be available. The following three variables are set in <span class="docbook_filename">OS/Makefile-Default</span>: </p> <div class="docbook_literallayout"><pre> X11=/usr/X11R6 XINCLUDE=-I$(X11)/include XLFLAGS=-L$(X11)/lib </pre></div> <p> These are overridden in some of the operating-system configuration files. For example, in <span class="docbook_filename">OS/Makefile-SunOS5</span> there is </p> <div class="docbook_literallayout"><pre> X11=/usr/openwin XINCLUDE=-I$(X11)/include XLFLAGS=-L$(X11)/lib -R$(X11)/lib </pre></div> <p> If you need to override the default setting for your operating system, place a definition of all three of these variables into your <span class="docbook_filename">Local/Makefile-<ostype></span> file. </p> <p> If you need to add any extra libraries to the link steps, these can be put in a variable called EXTRALIBS, which appears in all the link commands, but by default is not defined. In contrast, EXTRALIBS_EXIM is used only on the command for linking the main Exim binary, and not for any associated utilities. </p> <p> There is also DBMLIB, which appears in the link commands for binaries that use DBM functions (see also section <a href="ch04.html#SECTdb" title="4. Building and installing Exim">4.4</a>). Finally, there is EXTRALIBS_EXIMON, which appears only in the link step for the Exim monitor binary, and which can be used, for example, to include additional X11 libraries. </p> <p> The make file copes with rebuilding Exim correctly if any of the configuration files are edited. However, if an optional configuration file is deleted, it is necessary to touch the associated non-optional file (that is, <span class="docbook_filename">Local/Makefile</span> or <span class="docbook_filename">Local/eximon.conf</span>) before rebuilding. </p> </div> <div class="section"> <h3 id="SECID30" class="">13. OS-specific header files</h3> <p> The <span class="docbook_filename">OS</span> directory contains a number of files with names of the form <span class="docbook_filename">os.h-<ostype></span>. These are system-specific C header files that should not normally need to be changed. There is a list of macro settings that are recognized in the file <span class="docbook_filename">OS/os.configuring</span>, which should be consulted if you are porting Exim to a new operating system. </p> </div> <div class="section"> <h3 id="SECID31" class="">14. Overriding build-time options for the monitor</h3> <p> A similar process is used for overriding things when building the Exim monitor, where the files that are involved are </p> <div class="docbook_literallayout"><pre> <span class="docbook_filename">OS/eximon.conf-Default</span> <span class="docbook_filename">OS/eximon.conf-</span><<span class="docbook_emphasis">ostype</span>> <span class="docbook_filename">Local/eximon.conf</span> <span class="docbook_filename">Local/eximon.conf-</span><<span class="docbook_emphasis">ostype</span>> <span class="docbook_filename">Local/eximon.conf-</span><<span class="docbook_emphasis">archtype</span>> <span class="docbook_filename">Local/eximon.conf-</span><<span class="docbook_emphasis">ostype</span>>-<<span class="docbook_emphasis">archtype</span>> </pre></div> <p> As with Exim itself, the final three files need not exist, and in this case the <span class="docbook_filename">OS/eximon.conf-<ostype></span> file is also optional. The default values in <span class="docbook_filename">OS/eximon.conf-Default</span> can be overridden dynamically by setting environment variables of the same name, preceded by EXIMON_. For example, setting EXIMON_LOG_DEPTH in the environment overrides the value of LOG_DEPTH at run time. </p> </div> <div class="section"> <h3 id="SECID32" class="">15. Installing Exim binaries and scripts</h3> <p> The command <code class="docbook_literal">make install</code> runs the <span class="docbook_command">exim_install</span> script with no arguments. The script copies binaries and utility scripts into the directory whose name is specified by the BIN_DIRECTORY setting in <span class="docbook_filename">Local/Makefile</span>. The install script copies files only if they are newer than the files they are going to replace. The Exim binary is required to be owned by root and have the <span class="docbook_emphasis">setuid</span> bit set, for normal configurations. Therefore, you must run <code class="docbook_literal">make install</code> as root so that it can set up the Exim binary in this way. However, in some special situations (for example, if a host is doing no local deliveries) it may be possible to run Exim without making the binary setuid root (see chapter <a href="ch52.html" title="52. Security considerations">52</a> for details). </p> <p> Exim’s run time configuration file is named by the CONFIGURE_FILE setting in <span class="docbook_filename">Local/Makefile</span>. If this names a single file, and the file does not exist, the default configuration file <span class="docbook_filename">src/configure.default</span> is copied there by the installation script. If a run time configuration file already exists, it is left alone. If CONFIGURE_FILE is a colon-separated list, naming several alternative files, no default is installed. </p> <p> One change is made to the default configuration file when it is installed: the default configuration contains a router that references a system aliases file. The path to this file is set to the value specified by SYSTEM_ALIASES_FILE in <span class="docbook_filename">Local/Makefile</span> (<span class="docbook_filename">/etc/aliases</span> by default). If the system aliases file does not exist, the installation script creates it, and outputs a comment to the user. </p> <p> The created file contains no aliases, but it does contain comments about the aliases a site should normally have. Mail aliases have traditionally been kept in <span class="docbook_filename">/etc/aliases</span>. However, some operating systems are now using <span class="docbook_filename">/etc/mail/aliases</span>. You should check if yours is one of these, and change Exim’s configuration if necessary. </p> <p> The default configuration uses the local host’s name as the only local domain, and is set up to do local deliveries into the shared directory <span class="docbook_filename">/var/mail</span>, running as the local user. System aliases and <span class="docbook_filename">.forward</span> files in users’ home directories are supported, but no NIS or NIS+ support is configured. Domains other than the name of the local host are routed using the DNS, with delivery over SMTP. </p> <p> It is possible to install Exim for special purposes (such as building a binary distribution) in a private part of the file system. You can do this by a command such as </p> <div class="docbook_literallayout"><pre> make DESTDIR=/some/directory/ install </pre></div> <p> This has the effect of pre-pending the specified directory to all the file paths, except the name of the system aliases file that appears in the default configuration. (If a default alias file is created, its name <span class="docbook_emphasis">is</span> modified.) For backwards compatibility, ROOT is used if DESTDIR is not set, but this usage is deprecated. </p> <p> Running <span class="docbook_emphasis">make install</span> does not copy the Exim 4 conversion script <span class="docbook_emphasis">convert4r4</span>. You will probably run this only once if you are upgrading from Exim 3. None of the documentation files in the <span class="docbook_filename">doc</span> directory are copied, except for the info files when you have set INFO_DIRECTORY, as described in section <a href="ch04.html#SECTinsinfdoc" title="4. Building and installing Exim">4.16</a> below. </p> <p> For the utility programs, old versions are renamed by adding the suffix <span class="docbook_filename">.O</span> to their names. The Exim binary itself, however, is handled differently. It is installed under a name that includes the version number and the compile number, for example <span class="docbook_filename">exim-4.73-1</span>. The script then arranges for a symbolic link called <span class="docbook_filename">exim</span> to point to the binary. If you are updating a previous version of Exim, the script takes care to ensure that the name <span class="docbook_filename">exim</span> is never absent from the directory (as seen by other processes). </p> <p> If you want to see what the <span class="docbook_emphasis">make install</span> will do before running it for real, you can pass the <span class="docbook_option">-n</span> option to the installation script by this command: </p> <div class="docbook_literallayout"><pre> make INSTALL_ARG=-n install </pre></div> <p> The contents of the variable INSTALL_ARG are passed to the installation script. You do not need to be root to run this test. Alternatively, you can run the installation script directly, but this must be from within the build directory. For example, from the top-level Exim directory you could use this command: </p> <div class="docbook_literallayout"><pre> (cd build-SunOS5-5.5.1-sparc; ../scripts/exim_install -n) </pre></div> <p> There are two other options that can be supplied to the installation script. </p> <ul> <li> <p> <span class="docbook_option">-no_chown</span> bypasses the call to change the owner of the installed binary to root, and the call to make it a setuid binary. </p> </li> <li> <p> <span class="docbook_option">-no_symlink</span> bypasses the setting up of the symbolic link <span class="docbook_filename">exim</span> to the installed binary. </p> </li> </ul> <p> INSTALL_ARG can be used to pass these options to the script. For example: </p> <div class="docbook_literallayout"><pre> make INSTALL_ARG=-no_symlink install </pre></div> <p> The installation script can also be given arguments specifying which files are to be copied. For example, to install just the Exim binary, and nothing else, without creating the symbolic link, you could use: </p> <div class="docbook_literallayout"><pre> make INSTALL_ARG='-no_symlink exim' install </pre></div> </div> <div class="section"> <h3 id="SECTinsinfdoc" class="">16. Installing info documentation</h3> <p> Not all systems use the GNU <span class="docbook_emphasis">info</span> system for documentation, and for this reason, the Texinfo source of Exim’s documentation is not included in the main distribution. Instead it is available separately from the ftp site (see section <a href="ch01.html#SECTavail" title="1. Introduction">1.6</a>). </p> <p> If you have defined INFO_DIRECTORY in <span class="docbook_filename">Local/Makefile</span> and the Texinfo source of the documentation is found in the source tree, running <code class="docbook_literal">make install</code> automatically builds the info files and installs them. </p> </div> <div class="section"> <h3 id="SECID33" class="">17. Setting up the spool directory</h3> <p> When it starts up, Exim tries to create its spool directory if it does not exist. The Exim uid and gid are used for the owner and group of the spool directory. Sub-directories are automatically created in the spool directory as necessary. </p> </div> <div class="section"> <h3 id="SECID34" class="">18. Testing</h3> <p> Having installed Exim, you can check that the run time configuration file is syntactically valid by running the following command, which assumes that the Exim binary directory is within your PATH environment variable: </p> <div class="docbook_literallayout"><pre> exim -bV </pre></div> <p> If there are any errors in the configuration file, Exim outputs error messages. Otherwise it outputs the version number and build date, the DBM library that is being used, and information about which drivers and other optional code modules are included in the binary. Some simple routing tests can be done by using the address testing option. For example, </p> <div class="docbook_literallayout"><pre> <code class="docbook_literal">exim -bt</code> <<span class="docbook_emphasis">local username</span>> </pre></div> <p> should verify that it recognizes a local mailbox, and </p> <div class="docbook_literallayout"><pre> <code class="docbook_literal">exim -bt</code> <<span class="docbook_emphasis">remote address</span>> </pre></div> <p> a remote one. Then try getting it to deliver mail, both locally and remotely. This can be done by passing messages directly to Exim, without going through a user agent. For example: </p> <div class="docbook_literallayout"><pre> exim -v postmaster@your.domain.example From: user@your.domain.example To: postmaster@your.domain.example Subject: Testing Exim This is a test message. ^D </pre></div> <p> The <span class="docbook_option">-v</span> option causes Exim to output some verification of what it is doing. In this case you should see copies of three log lines, one for the message’s arrival, one for its delivery, and one containing “Completed”. </p> <p> If you encounter problems, look at Exim’s log files (<span class="docbook_emphasis">mainlog</span> and <span class="docbook_emphasis">paniclog</span>) to see if there is any relevant information there. Another source of information is running Exim with debugging turned on, by specifying the <span class="docbook_option">-d</span> option. If a message is stuck on Exim’s spool, you can force a delivery with debugging turned on by a command of the form </p> <div class="docbook_literallayout"><pre> <code class="docbook_literal">exim -d -M</code> <<span class="docbook_emphasis">exim-message-id</span>> </pre></div> <p> You must be root or an “admin user” in order to do this. The <span class="docbook_option">-d</span> option produces rather a lot of output, but you can cut this down to specific areas. For example, if you use <span class="docbook_option">-d-all+route</span> only the debugging information relevant to routing is included. (See the <span class="docbook_option">-d</span> option in chapter <a href="ch05.html" title="5. The Exim command line">5</a> for more details.) </p> <p> One specific problem that has shown up on some sites is the inability to do local deliveries into a shared mailbox directory, because it does not have the “sticky bit” set on it. By default, Exim tries to create a lock file before writing to a mailbox file, and if it cannot create the lock file, the delivery is deferred. You can get round this either by setting the “sticky bit” on the directory, or by setting a specific group for local deliveries and allowing that group to create files in the directory (see the comments above the <span class="docbook_command">local_delivery</span> transport in the default configuration file). Another approach is to configure Exim not to use lock files, but just to rely on <span class="docbook_function">fcntl()</span> locking instead. However, you should do this only if all user agents also use <span class="docbook_function">fcntl()</span> locking. For further discussion of locking issues, see chapter <a href="ch26.html" title="26. The appendfile transport">26</a>. </p> <p> One thing that cannot be tested on a system that is already running an MTA is the receipt of incoming SMTP mail on the standard SMTP port. However, the <span class="docbook_option">-oX</span> option can be used to run an Exim daemon that listens on some other port, or <span class="docbook_emphasis">inetd</span> can be used to do this. The <span class="docbook_option">-bh</span> option and the <span class="docbook_emphasis">exim_checkaccess</span> utility can be used to check out policy controls on incoming SMTP mail. </p> <p> Testing a new version on a system that is already running Exim can most easily be done by building a binary with a different CONFIGURE_FILE setting. From within the run time configuration, all other file and directory names that Exim uses can be altered, in order to keep it entirely clear of the production version. </p> </div> <div class="section"> <h3 id="SECID35" class="">19. Replacing another MTA with Exim</h3> <p> Building and installing Exim for the first time does not of itself put it in general use. The name by which the system’s MTA is called by mail user agents is either <span class="docbook_filename">/usr/sbin/sendmail</span>, or <span class="docbook_filename">/usr/lib/sendmail</span> (depending on the operating system), and it is necessary to make this name point to the <span class="docbook_emphasis">exim</span> binary in order to get the user agents to pass messages to Exim. This is normally done by renaming any existing file and making <span class="docbook_filename">/usr/sbin/sendmail</span> or <span class="docbook_filename">/usr/lib/sendmail</span> a symbolic link to the <span class="docbook_emphasis">exim</span> binary. It is a good idea to remove any setuid privilege and executable status from the old MTA. It is then necessary to stop and restart the mailer daemon, if one is running. </p> <p> Some operating systems have introduced alternative ways of switching MTAs. For example, if you are running FreeBSD, you need to edit the file <span class="docbook_filename">/etc/mail/mailer.conf</span> instead of setting up a symbolic link as just described. A typical example of the contents of this file for running Exim is as follows: </p> <div class="docbook_literallayout"><pre> sendmail /usr/exim/bin/exim send-mail /usr/exim/bin/exim mailq /usr/exim/bin/exim -bp newaliases /usr/bin/true </pre></div> <p> Once you have set up the symbolic link, or edited <span class="docbook_filename">/etc/mail/mailer.conf</span>, your Exim installation is “live”. Check it by sending a message from your favourite user agent. </p> <p> You should consider what to tell your users about the change of MTA. Exim may have different capabilities to what was previously running, and there are various operational differences such as the text of messages produced by command line options and in bounce messages. If you allow your users to make use of Exim’s filtering capabilities, you should make the document entitled <span class="docbook_emphasis">Exim’s interface to mail filtering</span> available to them. </p> </div> <div class="section"> <h3 id="SECID36" class="">20. Upgrading Exim</h3> <p> If you are already running Exim on your host, building and installing a new version automatically makes it available to MUAs, or any other programs that call the MTA directly. However, if you are running an Exim daemon, you do need to send it a HUP signal, to make it re-execute itself, and thereby pick up the new binary. You do not need to stop processing mail in order to install a new version of Exim. The install script does not modify an existing runtime configuration file. </p> </div> <div class="section"> <h3 id="SECID37" class="">21. Stopping the Exim daemon on Solaris</h3> <p> The standard command for stopping the mailer daemon on Solaris is </p> <div class="docbook_literallayout"><pre> /etc/init.d/sendmail stop </pre></div> <p> If <span class="docbook_filename">/usr/lib/sendmail</span> has been turned into a symbolic link, this script fails to stop Exim because it uses the command <span class="docbook_emphasis">ps -e</span> and greps the output for the text “sendmail”; this is not present because the actual program name (that is, “exim”) is given by the <span class="docbook_emphasis">ps</span> command with these options. A solution is to replace the line that finds the process id with something like </p> <div class="docbook_literallayout"><pre> pid=`cat /var/spool/exim/exim-daemon.pid` </pre></div> <p> to obtain the daemon’s pid directly from the file that Exim saves it in. </p> <p> Note, however, that stopping the daemon does not “stop Exim”. Messages can still be received from local processes, and if automatic delivery is configured (the normal case), deliveries will still occur. </p> </div> </div> <a class="previous_page" href="ch03.html"><-previous</a><a class="next_page" href="ch05.html">next-></a> </div></div> <iframe id="branding" name="branding" src="../../../../branding/branding.html" height="0" frameborder="no" scrolling="no"></iframe><div id="footer">Website design by <a href="https://secure.grepular.com/">Mike Cardwell</a>, of <a href="http://cardwellit.com/">Cardwell IT Ltd.</a> </div> <div class="left_bar"></div> <div class="right_bar"></div> <div id="toc"> <ul class="hidden"></ul> <img src="../../../../doc/contents.png" width="16" height="155"> </div> </div> <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js"></script><script type="text/javascript" src="../../../../common.js"></script><script type="text/javascript" src="../../../../doc/chapter.js"></script> </body> </html>