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>Getting EximUp and Running</TITLE
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><DIV
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><H1
><A
NAME="X-087-2-EXIM"
>Chapter 19. Getting EximUp and Running</A
></H1
><DIV
CLASS="TOC"
><DL
><DT
><B
>Table of Contents</B
></DT
><DT
>19.1. <A
HREF="x15909.html"
>Running Exim</A
></DT
><DT
>19.2. <A
HREF="x15964.html"
>If Your Mail Doesn't Get Through</A
></DT
><DT
>19.3. <A
HREF="x15999.html"
>Compiling Exim</A
></DT
><DT
>19.4. <A
HREF="x-087-2-exim.queue.html"
>Mail Delivery Modes</A
></DT
><DT
>19.5. <A
HREF="x-087-2-exim.options.html"
>Miscellaneous config Options</A
></DT
><DT
>19.6. <A
HREF="x-087-2-exim.delivery.html"
>Message Routing and Delivery</A
></DT
><DD
><DL
><DT
>19.6.1. <A
HREF="x-087-2-exim.delivery.html#X-087-2-EXIM.ROUTING"
>Routing Messages</A
></DT
><DT
>19.6.2. <A
HREF="x-087-2-exim.delivery.html#X-087-2-EXIM.DIRECTORS"
>Delivering Messages to Local Addresses</A
></DT
><DT
>19.6.3. <A
HREF="x-087-2-exim.delivery.html#AEN16228"
>Alias Files</A
></DT
><DT
>19.6.4. <A
HREF="x-087-2-exim.delivery.html#X-087-2-EXIM.DIRECTOR.MAILING-LISTS"
>Mailing Lists</A
></DT
></DL
></DD
><DT
>19.7. <A
HREF="x16298.html"
>Protecting Against Mail Spam</A
></DT
><DT
>19.8. <A
HREF="x-087-2-exim.simple.html"
>UUCP Setup</A
></DT
></DL
></DIV
><P
>This chapter gives you a quick introduction to setting up Exim and an overview
of its functionality. Although Exim is largely compatible with
<B
CLASS="COMMAND"
>sendmail</B
> in its behavior, its configuration files are
completely different.</P
><P
>
The main configuration file is usually called
<TT
CLASS="FILENAME"
>/etc/exim.conf</TT
> or <TT
CLASS="FILENAME"
>/etc/exim/config</TT
>
in most Linux distributions, or <TT
CLASS="FILENAME"
>/usr/lib/exim/config</TT
> in
older configurations. You can find out where the configuration file is by
running the command:
<TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="SCREEN"
>$ <TT
CLASS="USERINPUT"
><B
>exim -bP configure_file</B
></TT
></PRE
></TD
></TR
></TABLE
></P
><P
>You may have to edit the configuration file to reflect values specific to your
site. In most common configurations there isn't a great deal to change, and a
working configuration should rarely have to be modified.</P
><P
>&#13;By default, Exim processes and delivers all incoming mail immediately. If you
have relatively high traffic, you may instead have Exim collect all messages
in the so-called <I
CLASS="EMPHASIS"
>queue</I
>, and process them at regular
intervals only.</P
><P
>&#13;When handling mail within a TCP/IP network, Exim is frequently run in daemon
mode: at system boot time, it is invoked from
<TT
CLASS="FILENAME"
>/etc/init.d/exim</TT
><A
NAME="X-087-2-FNEX01"
HREF="#FTN.X-087-2-FNEX01"
>[1]</A
>
and puts itself in the background, where it waits for incoming TCP connections
on the SMTP port (usually port 25). This is beneficial whenever you expect to
have a significant amount of traffic because Exim doesn't have to start up
for every incoming connection. Alternatively, <B
CLASS="COMMAND"
>inetd</B
> could
manage the SMTP port and have it spawn Exim whenever there is a connection
on this port. This configuration might be useful when you have limited
memory and low mail traffic volumes.</P
><P
>&#13;
Exim has a complicated set of command-line options, including many
that match those of sendmail. Instead of trying to put together
exactly the right options for your needs, you can implement the most
common types of operation by invoking traditional commands like
<B
CLASS="COMMAND"
>rmail</B
> or <B
CLASS="COMMAND"
>rsmtp</B
>. These are
symbolic links to Exim (or if they're not, you can easily link
them to it). When you run one of the commands, Exim checks the
name you used to invoke it and sets the proper options itself.</P
><P
>There are two links to Exim that you should have under all circumstances:
<B
CLASS="COMMAND"
>/usr/bin/rmail</B
> and <B
CLASS="COMMAND"
>/usr/sbin/sendmail</B
>.<A
NAME="X-087-2-FNEX02"
HREF="#FTN.X-087-2-FNEX02"
>[2]</A
>
When you compose and send a mail message with a user agent like
<B
CLASS="COMMAND"
>elm</B
>, the message is piped to <B
CLASS="COMMAND"
>sendmail</B
>
or <B
CLASS="COMMAND"
>rmail</B
> for delivery, which is why both
<B
CLASS="COMMAND"
>/usr/sbin/sendmail</B
> and <B
CLASS="COMMAND"
>/usr/bin/rmail</B
>
should point to Exim. The list of recipients for the message is passed to Exim
on the command line.<A
NAME="X-087-2-FNEX03"
HREF="#FTN.X-087-2-FNEX03"
>[3]</A
>
The same happens with mail coming in via UUCP. You can set up the required
pathnames to point to Exim by typing the following at a shell prompt:
<TABLE
BORDER="0"
BGCOLOR="#E0E0E0"
WIDTH="100%"
><TR
><TD
><PRE
CLASS="SCREEN"
>$ <TT
CLASS="USERINPUT"
><B
>ln -s /usr/sbin/exim /usr/bin/rmail</B
></TT
>
$ <TT
CLASS="USERINPUT"
><B
>ln -s /usr/sbin/exim /usr/sbin/sendmail</B
></TT
></PRE
></TD
></TR
></TABLE
></P
><P
>If you want to dig further into the details of configuring Exim, you should
consult the full Exim specification. If this isn't included in your favorite
Linux distribution, you can get it from the source to Exim, or read it online
from Exim's web site at
<SPAN
CLASS="SYSTEMITEM"
>http://www.exim.org</SPAN
>.</P
></DIV
><H3
CLASS="FOOTNOTES"
>Notes</H3
><TABLE
BORDER="0"
CLASS="FOOTNOTES"
WIDTH="100%"
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.X-087-2-FNEX01"
HREF="x-087-2-exim.html#X-087-2-FNEX01"
>[1]</A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
>Other possible locations are
<TT
CLASS="FILENAME"
>/etc/rc.d/init.d</TT
> and
<TT
CLASS="FILENAME"
>rc.inet2</TT
>. The latter is common on systems
using a BSD-style structure for system administration files in the
<TT
CLASS="FILENAME"
>/etc</TT
> directory.</P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.X-087-2-FNEX02"
HREF="x-087-2-exim.html#X-087-2-FNEX02"
>[2]</A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
>This is the new standard location of <B
CLASS="COMMAND"
>sendmail</B
> according to
the Linux File System Standard. Another common location is
<TT
CLASS="FILENAME"
>/usr/lib/sendmail</TT
>, which is likely to be used by mail
programs that are not specially configured for Linux.
You can define both filenames as symbolic links to
Exim so that programs and scripts invoking <I
CLASS="EMPHASIS"
>sendmail</I
> will instead
invoke Exim to do the same things.</P
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="5%"
><A
NAME="FTN.X-087-2-FNEX03"
HREF="x-087-2-exim.html#X-087-2-FNEX03"
>[3]</A
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
WIDTH="95%"
><P
>Some user agents, however, use the SMTP protocol to pass messages to the
transport agent, calling it with the <TT
CLASS="OPTION"
>&#8211;bs</TT
> option.</P
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