diff options
| author | Jim Mock <jim@FreeBSD.org> | 1999-12-17 20:10:29 +0000 |
|---|---|---|
| committer | Jim Mock <jim@FreeBSD.org> | 1999-12-17 20:10:29 +0000 |
| commit | 04d258c61bc99f8494c99ea64338f20a4ad9a4b6 (patch) | |
| tree | f2f408624ed2a00d16188b000287be5d8e1c9ce4 /en_US.ISO_8859-1 | |
| parent | baf6d86f6e27644d1aac4cb6b22607c626d48096 (diff) | |
| download | doc-04d258c61bc99f8494c99ea64338f20a4ad9a4b6.tar.gz doc-04d258c61bc99f8494c99ea64338f20a4ad9a4b6.zip | |
Yet another rewrite/restructure, this time of the mail chapter. I
apologize to the translation teams for not doing style and content in
two separate commits, but it's not very realistic to do so when so much
has changed.
Reviewed by: jkh
Notes
Notes:
svn path=/head/; revision=6216
Diffstat (limited to 'en_US.ISO_8859-1')
| -rw-r--r-- | en_US.ISO_8859-1/books/handbook/mail/chapter.sgml | 897 |
1 files changed, 407 insertions, 490 deletions
diff --git a/en_US.ISO_8859-1/books/handbook/mail/chapter.sgml b/en_US.ISO_8859-1/books/handbook/mail/chapter.sgml index 1b96df4f34..227ed84619 100644 --- a/en_US.ISO_8859-1/books/handbook/mail/chapter.sgml +++ b/en_US.ISO_8859-1/books/handbook/mail/chapter.sgml @@ -1,460 +1,203 @@ <!-- The FreeBSD Documentation Project - $FreeBSD: doc/en_US.ISO_8859-1/books/handbook/mail/chapter.sgml,v 1.14 1999/09/06 06:53:01 peter Exp $ + $FreeBSD: doc/en_US.ISO_8859-1/books/handbook/mail/chapter.sgml,v 1.15 1999/11/07 01:54:50 chris Exp $ --> <chapter id="mail"> <title>Electronic Mail</title> - <para><emphasis>Contributed by &a.wlloyd;.</emphasis></para> - - <para>Electronic Mail configuration is the subject of many <link - linkend="bibliography">System Administration</link> books. If you plan - on doing anything beyond setting up one mailhost for your network, you - need industrial strength help.</para> - - <para>Some parts of E-Mail configuration are controlled in the Domain Name - System (DNS). If you are going to run your own own DNS server check out - <filename>/etc/namedb</filename> and <command>man -k named</command> for - more information.</para> - + <para><emphasis>Rewritten by &a.jim;, 02 December 1999. Original work + done by &a.wlloyd;.</emphasis></para> + <sect1> - <title>Basic Information</title> + <title>Synopsis</title> + + <para>Electronic Mail, better known as email, is one of the most + widely used forms of communication today. Millions of people use + email every day, and chances are if you are reading this online, + you fall into that category and probably even have more than one + email address.</para> + + <para>Electronic Mail configuration is the subject of many <link + linkend="bibliography">System Administration</link> books. If you + plan on doing anything beyond setting up one mailhost for your + network, you need industrial strength help.</para> + + <para>Some parts of email configuration are controlled in the Domain + Name System (DNS). If you are going to run your own DNS server, be + sure to read <filename>/etc/namedb</filename> and <command>man -k + named</command>.</para> + </sect1> + + <sect1 id="mail-using"> + <title>Using Electronic Mail</title> - <para>These are the major programs involved in an E-Mail exchange. A - “mailhost” is a server that is responsible for delivering - and receiving all email for your host, and possibly your network.</para> + <para>There are five major parts involved in an email exchange. They + are: <link linkend="mail-mua">the user program</link>, <link + linkend="mail-mta">the server daemon</link>, <link + linkend="mail-dns">DNS</link>, <link linkend="mail-receive">a pop or + IMAP daemon</link>, and of course, <link linkend="mail-host">the + mailhost itself</link>.</para> - <sect2> - <title>User program</title> - - <para>This is a program like <application >elm</application>, - <application>pine</application>, <application>mail</application>, or - something more sophisticated like a WWW browser. This program will - simply pass off all e-mail transactions to the local - “mailhost” , either by calling <command>sendmail</command> - or delivering it over TCP.</para> + <sect2 id="mail-mua"> + <title>The User Program</title> + + <para>This includes command line programs such as + <application>mutt</application>, <application>pine</application>, + <application>elm</application>, and + <application>mail</application>, and GUI programs such as + <application>balsa</application>, + <application>xfmail</application> to name a few, and something + more “sophisticated” like a WWW browser. These + programs simply pass off the email transactions to the local <link + linkend="mail-host">“mailhost”</link>, either by + calling one of the <link linkend="mail-mta">server daemons</link> + available or delivering it over TCP.</para> </sect2> - <sect2> + <sect2 id="mail-mta"> <title>Mailhost Server Daemon</title> - - <para>Usually this program is <command>sendmail</command> or - <command>smail</command> running in the background. Turn it off or - change the command line options in <filename>/etc/rc.conf</filename> - (or, prior to FreeBSD 2.2.2, <filename>/etc/sysconfig</filename>). It - is best to leave it on, unless you have a specific reason to want it - off. Example: You are building a <link - linkend="firewalls">Firewall</link>.</para> - - <para>You should be aware that <command>sendmail</command> is a - potential weak link in a secure site. Some versions of - <command>sendmail</command> have known security problems.</para> - - <para><command>sendmail</command> does two jobs. It looks after - delivering and receiving mail.</para> - - <para>If <command>sendmail</command> needs to deliver mail off your site - it will look up in the DNS to determine the actual host that will - receive mail for the destination.</para> - - <para>If it is acting as a delivery agent <command>sendmail</command> - will take the message from the local queue and deliver it across the - Internet to another sendmail on the receivers computer.</para> + + <para>This is usually <application>sendmail</application> (by + default with FreeBSD) or one of the other mail server daemons such + as <application>qmail</application>, + <application>postfix</application>, or + <application>exim</application>. There are others, but those are + the most widely used.</para> + + <para>The server daemon usually has two functions—it looks + after receiving incoming mail and delivers outgoing mail. It does + not allow you to connect to it via POP or IMAP to read your mail. + You need an additional <link linkend="mail-receive">daemon</link> + for that.</para> + + <para>Be aware that some older versions of + <application>sendmail</application> have some serious security + problems, however as long you run a current version of it you + should not have any problems. As always, it is a good idea to + stay up-to-date with any software you run.</para> </sect2> - - <sect2> - <title>DNS — Name Service</title> - - <para>The Domain Name System and its daemon <command>named</command>, - contain the database mapping hostname to IP address, and hostname to - mailhost. The IP address is specified in an A record. The MX record - specifies the mailhost that will receive mail for you. If you do not - have a MX record mail for your hostname, the mail will be delivered to - your host directly.</para> - - <para>Unless you are running your own DNS server, you will not be able - to change any information in the DNS yourself. If you are using an - Internet Provider, speak to them.</para> + + <sect2 id="mail-dns"> + <title>Email and DNS</title> + + <para>The Domain Name System (DNS) and its daemon + <command>named</command> play a large role in the delivery of + email. In order to deliver mail from your site to another, the + server daemon will look up the site in the DNS to determine the + host that will receive mail for the destination.</para> + + <para>It works the same way when you have mail sent to you. The DNS + contains the database mapping hostname to an IP address, and a + hostname to mailhost. The IP address is specified in an A record. + The MX (Mail eXchanger) record specifies the mailhost that will + receive mail for you. If you do not have an MX record for your + hostname, the mail will be delivered directly to your host.</para> </sect2> - - <sect2> - <title>POP Servers</title> - - <para>This program gets the mail from your mailbox and gives it to your - browser. If you want to run a POP server on your computer, you will - need to do 2 things.</para> - + + <sect2 id="mail-receive"> + <title>Receiving Mail</title> + + <para>Receiving mail for your domain is done by the mail host. It + will collect mail sent to you and store it for reading or pickup. + In order to pick the stored mail up, you will need to connect to + the mail host. This is done by either using POP or IMAP. If you + want to read mail directly on the mail host, then a POP or IMAP + server is not needed.</para> + + <para>If you want to run a POP or IMAP server, there are two things + you need to do:</para> + <procedure> - <step> - <para>Get pop software from the <ulink - url="../ports/mail.html">Ports collection</ulink> that can be - found in <filename>/usr/ports</filename> or packages collection. - This handbook section has a complete reference on the <link - linkend="ports">Ports</link> system.</para> + <step> + <para>Get a POP or IMAP daemon from the <ulink + url="../ports/mail.html">Ports Collection</ulink> and install + it on your system.</para> </step> <step> - <para>Modify <filename>/etc/inetd.conf</filename> to load the POP - server.</para> + <para>Modify <filename>/etc/inetd.conf</filename> to load the + POP or IMAP server.</para> </step> </procedure> - - <para>The pop program will have instructions with it. Read them.</para> </sect2> - </sect1> - - <sect1> - <title>Configuration</title> - <sect2> - <title>Basic</title> - - <para>As your FreeBSD system comes “out of the box”[TM], you - should be able to send E-mail to external hosts as long as you have - <filename>/etc/resolv.conf</filename> setup or are running a name - server. If you want to have mail for your host delivered to your - specific host,there are two methods:</para> - - <itemizedlist> - <listitem> - <para>Run a name server (<command>man -k named</command>) and have - your own domain <hostid role="domainname">smallminingco.com - </hostid></para> - </listitem> + <sect2 id="mail-host"> + <title>The Mail Host</title> - <listitem> - <para>Get mail delivered to the current DNS name for your host. Ie: - <hostid role="fqdn">dorm6.ahouse.school.edu </hostid></para> - </listitem> - </itemizedlist> - - <para>No matter what option you choose, to have mail delivered directly - to your host, you must be a full Internet host. You must have a - permanent IP address. IE: NO dynamic PPP. If you are behind a - firewall, the firewall must be passing on smtp traffic to you. From - <filename>/etc/services</filename>:</para> - - <programlisting> -smtp 25/tcp mail #Simple Mail Transfer</programlisting> - - <para>If you want to receive mail at your host itself, you must make - sure that the DNS MX entry points to your host address, or there is no - MX entry for your DNS name.</para> - - <para>Try this:</para> - - <screen>&prompt.root; <userinput>hostname</userinput> -newbsdbox.FreeBSD.org -&prompt.root; <userinput>host newbsdbox.FreeBSD.org</userinput> -newbsdbox.FreeBSD.org has address 204.216.27.xx</screen> - - <para>If that is all that comes out for your machine, mail directory to - <email>root@newbsdbox.FreeBSD.org</email> will work no - problems.</para> - - <para>If instead, you have this:</para> - - <screen>&prompt.root; <userinput>host newbsdbox.FreeBSD.org</userinput> -newbsdbox.FreeBSD.org has address 204.216.27.xx -newbsdbox.FreeBSD.org mail is handled (pri=10) by freefall.FreeBSD.org</screen> - - <para>All mail sent to your host directly will end up on - <hostid>freefall</hostid>, under the same username.</para> - - <para>This information is setup in your domain name server. This should - be the same host that is listed as your primary nameserver in - <filename>/etc/resolv.conf</filename></para> - - <para>The DNS record that carries mail routing information is the Mail - eXchange entry. If no MX entry exists, mail will be delivered directly - to the host by way of the Address record.</para> - - <para>The MX entry for <hostid role="fqdn">freefall.FreeBSD.org</hostid> - at one time.</para> - - <programlisting> -freefall MX 30 mail.crl.net -freefall MX 40 agora.rdrop.com -freefall HINFO Pentium FreeBSD -freefall MX 10 freefall.FreeBSD.org -freefall MX 20 who.cdrom.com -freefall A 204.216.27.xx -freefall CNAME www.FreeBSD.org</programlisting> - - <para><hostid>freefall</hostid> has many MX entries. The lowest MX - number gets the mail in the end. The others will queue mail - temporarily, if <hostid>freefall</hostid> is busy or down.</para> - - <para>Alternate MX sites should have separate connections to the - Internet, to be most useful. An Internet Provider or other friendly - site can provide this service.</para> - - <para><command>dig</command>, <command>nslookup</command>, and - <command>host</command> are your friends.</para> - </sect2> - - <sect2 id="mail-domain"> - <title>Mail for your Domain (Network).</title> - - <para>To setup up a network mailhost, you need to direct the mail from - arriving at all the workstations. In other words, you want to hijack - all mail for <hostid role="domainname">*.smallminingco.com </hostid> - and divert it to one machine, your “mailhost”.</para> - - <para>The network users on their workstations will most likely pick up - their mail over POP or telnet.</para> - - <para>A user account with the <emphasis>same username</emphasis> should - exist on both machines. Please use <command>adduser</command> to do - this as required. If you set the <literal>shell</literal> to - <literal>/nonexistent</literal> the user will not be allowed to - login.</para> - - <para>The mailhost that you will be using must be designated the - Mail eXchange for each workstation. This must be arranged in DNS (ie - BIND, named). Please refer to a Networking book for in-depth - information.</para> - - <para>You basically need to add these lines in your DNS server.</para> - - <programlisting> -pc24.smallminingco.com A <replaceable>xxx.xxx.xxx.xxx</replaceable> ; Workstation ip - MX 10 smtp.smallminingco.com ; Your mailhost</programlisting> - - <para>You cannot do this yourself unless you are running a DNS server. - If you do not want to run a DNS server, get somebody else like your - Internet Provider to do it.</para> - - <para>This will redirect mail for the workstation to the Mail eXchange - host. It does not matter what machine the A record points to, the mail - will be sent to the MX host.</para> - - <para>This feature is used to implement Virtual E-Mail Hosting.</para> - - <para>Example</para> - - <para>I have a customer with domain foo.bar and I want all mail for - foo.bar to be sent to my machine smtp.smalliap.com. You must make an - entry in your DNS server like:</para> - - <programlisting> -foo.bar MX 10 smtp.smalliap.com ; your mailhost</programlisting> - - <para>The A record is not needed if you only want E-Mail for the domain. - IE: Don't expect <command>ping foo.bar</command> to work unless an - Address record for <filename>foo.bar</filename> exists as well.</para> - - <para>On the mailhost that actually accepts mail for final delivery to a - mailbox, <command>sendmail</command> must be told what hosts it will - be accepting mail for.</para> - - <para>Add <literal>pc24.smallminingco.com</literal> to - <filename>/etc/sendmail.cw</filename> (if you are using - <literal>FEATURE(use_cw_file)</literal>), or add a <literal>Cw - myhost.smalliap.com</literal> line to - <filename>/etc/sendmail.cf</filename></para> - - <para>If you plan on doing anything serious with - <command>sendmail</command> you should install the - <command>sendmail</command> source. The source has plenty of - documentation with it. You will find information on getting - <command>sendmail</command> source from <link - linkend="sendmailuucp">the UUCP information</link>.</para> - </sect2> - - <sect2 id="sendmailuucp"> - <title>Setting up UUCP.</title> - - <para><emphasis>Stolen from the FAQ.</emphasis></para> - - <para>The sendmail configuration that ships with FreeBSD is suited for - sites that connect directly to the Internet. Sites that wish to - exchange their mail via UUCP must install another - <command>sendmail</command> configuration file.</para> - - <para>Tweaking <filename>/etc/sendmail.cf</filename> manually is - considered something for purists. Sendmail version 8 comes with a new - approach of generating config files via some <command>m4</command> - preprocessing, where the actual hand-crafted configuration is on a - higher abstraction level. You should use the configuration files under - <filename>/usr/src/usr.sbin/sendmail/cf</filename>.</para> - - <para>If you did not install your system with full sources, the - <command>sendmail</command> config stuff has been broken out into a - separate source distribution tarball just for you. Assuming you have - your CD-ROM mounted, do:</para> - - <screen>&prompt.root; <userinput>cd /usr/src</userinput> -&prompt.root; <userinput>tar -xvzf /cdrom/dists/src/ssmailcf.aa</userinput></screen> - - <para>Do not panic, this is only a few hundred kilobytes in size. The - file <filename>README</filename> in the <filename>cf</filename> - directory can serve as a basic introduction to m4 - configuration.</para> - - <para>For UUCP delivery, you are best advised to use the - <emphasis>mailertable</emphasis> feature. This constitutes a database - that <command>sendmail</command> can use to base its routing decision - upon.</para> - - <para>First, you have to create your <filename>.mc</filename> file. The - directory <filename>/usr/src/usr.sbin/sendmail/cf/cf</filename> is the - home of these files. Look around, there are already a few examples. - Assuming you have named your file <filename>foo.mc</filename>, all you - need to do in order to convert it into a valid - <filename>sendmail.cf</filename> is:</para> - - <screen>&prompt.root; <userinput>cd /usr/src/usr.sbin/sendmail/cf/cf</userinput> -&prompt.root; <userinput>make foo.cf</userinput></screen> - - <para>If you don't have a <filename>/usr/obj</filename> hierarchy, - then:</para> - - <screen>&prompt.root; <userinput>cp foo.cf /etc/sendmail.cf</userinput></screen> - - <para>Otherwise:</para> - - <screen>&prompt.root; <userinput>cp /usr/obj/`pwd`/foo.cf /etc/sendmail.cf</userinput></screen> - - <para>A typical <filename>.mc</filename> file might look like:</para> - - <programlisting> -include(`../m4/cf.m4') -VERSIONID(`<replaceable>Your version number</replaceable>') -OSTYPE(bsd4.4) - -FEATURE(nodns) -FEATURE(nocanonify) -FEATURE(mailertable) - -define(`UUCP_RELAY', <replaceable>your.uucp.relay</replaceable>) -define(`UUCP_MAX_SIZE', 200000) - -MAILER(local) -MAILER(smtp) -MAILER(uucp) - -Cw <replaceable>your.alias.host.name</replaceable> -Cw <replaceable>youruucpnodename.UUCP</replaceable></programlisting> - - <para>The <literal>nodns</literal> and <literal>nocanonify</literal> - features will prevent any usage of the DNS during mail delivery. The - <literal>UUCP_RELAY</literal> clause is needed for bizarre reasons, do - not ask. Simply put an Internet hostname there that is able to handle - .UUCP pseudo-domain addresses; most likely, you will enter the mail - relay of your ISP there.</para> - - <para>Once you have this, you need this file called - <filename>/etc/mailertable</filename>. A typical example of this - gender again:</para> - - <programlisting> -# -# makemap hash /etc/mailertable.db < /etc/mailertable -# -horus.interface-business.de uucp-dom:horus -.interface-business.de uucp-dom:if-bus -interface-business.de uucp-dom:if-bus -.heep.sax.de smtp8:%1 horus.UUCP -uucp-dom:horus if-bus.UUCP -uucp-dom:if-bus . uucp-dom:sax</programlisting> - - <para>As you can see, this is part of a real-life file. The first three - lines handle special cases where domain-addressed mail should not be - sent out to the default route, but instead to some UUCP neighbor in - order to “shortcut” the delivery path. The next line - handles mail to the local Ethernet domain that can be delivered using - SMTP. Finally, the UUCP neighbors are mentioned in the .UUCP - pseudo-domain notation, to allow for a - <literal>uucp-neighbor!recipient</literal> override of the default - rules. The last line is always a single dot, matching everything else, - with UUCP delivery to a UUCP neighbor that serves as your universal - mail gateway to the world. All of the node names behind the - <literal>uucp-dom:</literal> keyword must be valid UUCP neighbors, as - you can verify using the command <command>uuname</command>.</para> - - <para>As a reminder that this file needs to be converted into a DBM - database file before being usable, the command line to accomplish this - is best placed as a comment at the top of the - <filename>mailertable</filename>. You always have to execute this - command each time you change your - <filename>mailertable</filename>.</para> - - <para>Final hint: if you are uncertain whether some particular mail - routing would work, remember the <option>-bt</option> option to - <command>sendmail</command>. It starts <command>sendmail</command> in - “address test mode”; simply enter <literal>0</literal>, - followed by the address you wish to test for the mail routing. The - last line tells you the used internal mail agent, the destination host - this agent will be called with, and the (possibly translated) address. - Leave this mode by typing Control-D.</para> - - <screen>&prompt.user; <userinput>sendmail -bt</userinput> -ADDRESS TEST MODE (ruleset 3 NOT automatically invoked) -Enter <ruleset> <address> -<prompt>></prompt> <userinput>0 foo@interface-business.de</userinput> -rewrite: ruleset 0 input: foo @ interface-business . de -… -rewrite: ruleset 0 returns: $# uucp-dom $@ if-bus $: foo < @ interface-business . de</screen> + <para>The mail host is the name given to a server that is + responsible for delivering and receiving mail for your host, and + possibly your network.</para> </sect2> </sect1> - <sect1 id="mailfaq"> - <title>FAQ</title> - - <para><emphasis>Migration from FAQ.</emphasis></para> - - <sect2> - <title>Why do I have to use the FQDN for hosts on my site?</title> - - <para>You will probably find that the host is actually in a different - domain; for example, if you are in <hostid - role="fqdn">foo.bar.edu</hostid> and you wish to reach a host called - <hostid>mumble</hostid> in the <hostid - role="domainname">bar.edu</hostid> domain, you will have to refer to - it by the fully-qualified domain name, <hostid + <sect1 id="mail-trouble"> + <title>Troubleshooting</title> + + <para>Here are some frequently asked questions and answers. These + have been migrated from the <ulink url="../FAQ/">FAQ</ulink>.</para> + + <qandaset> + <qandaentry> + <question> + <para>Why do I have to use the FQDN for hosts on my site?</para> + </question> + + <answer> + <para>You will probably find that the host is actually in a + different domain; for example, if you are in + <hostid role="fqdn">foo.bar.edu</hostid> and you wish to reach + a host called <hostid>mumble</hostid> in the <hostid + role="domainname">bar.edu</hostid> domain, you will have to + refer to it by the fully-qualified domain name, <hostid role="fqdn">mumble.bar.edu</hostid>, instead of just - <hostid>mumble</hostid>.</para> - - <para>Traditionally, this was allowed by BSD BIND resolvers. However the - current version of <application>BIND</application> that ships with - FreeBSD no longer provides default abbreviations for non-fully - qualified domain names other than the domain you are in. So an - unqualified host <hostid>mumble</hostid> must either be found as - <hostid role="fqdn">mumble.foo.bar.edu</hostid>, or it will be - searched for in the root domain.</para> - - <para>This is different from the previous behavior, where the search - continued across <hostid role="domainname">mumble.bar.edu</hostid>, - and <hostid role="domainname">mumble.edu</hostid>. Have a look at RFC - 1535 for why this was considered bad practice, or even a security - hole.</para> - - <para>As a good workaround, you can place the line - - <programlisting> + <hostid>mumble</hostid>.</para> + + <para>Traditionally, this was allowed by BSD BIND resolvers. + However the current version of <application>BIND</application> + that ships with FreeBSD no longer provides default abbreviations + for non-fully qualified domain names other than the domain you + are in. So an unqualified host <hostid>mumble</hostid> must + either be found as <hostid + role="fqdn">mumble.foo.bar.edu</hostid>, or it will be searched + for in the root domain.</para> + + <para>This is different from the previous behavior, where the + search continued across <hostid + role="domainname">mumble.bar.edu</hostid>, and <hostid + role="domainname">mumble.edu</hostid>. Have a look at RFC 1535 + for why this was considered bad practice, or even a security + hole.</para> + + <para>As a good workaround, you can place the line: + + <programlisting> search foo.bar.edu bar.edu</programlisting> - - instead of the previous - - <programlisting> + + instead of the previous: + + <programlisting> domain foo.bar.edu</programlisting> - - into your <filename>/etc/resolv.conf</filename>. However, make sure - that the search order does not go beyond the “boundary between - local and public administration”, as RFC 1535 calls it.</para> - </sect2> - - <sect2> - <title>Sendmail says <errorname>mail loops back to - myself</errorname></title> - - <para>This is answered in the sendmail FAQ as follows:</para> + + into your <filename>/etc/resolv.conf</filename>. However, make + sure that the search order does not go beyond the + “boundary between local and public administration”, + as RFC 1535 calls it.</para> + </answer> + </qandaentry> + + <qandaentry> + <question> + <para>Sendmail says <errorname>mail loops back to + myself</errorname></para> + </question> + + <answer> + <para>This is answered in the sendmail FAQ as follows:</para> - <programlisting> -* I am getting "Local configuration error" messages, such as: + <programlisting> +* I am getting “Local configuration error” messages, such as: 553 relay.domain.net config error: mail loops back to myself 554 <user@domain.net>... Local configuration error @@ -465,65 +208,70 @@ You have asked mail to the domain (e.g., domain.net) to be forwarded to a specific host (in this case, relay.domain.net) by using an MX record, but the relay machine does not recognize itself as domain.net. Add domain.net to /etc/sendmail.cw -(if you are using FEATURE(use_cw_file)) or add "Cw domain.net" +(if you are using FEATURE(use_cw_file)) or add “Cw domain.net” to /etc/sendmail.cf.</programlisting> - - <para>The sendmail FAQ is in - <filename>/usr/src/usr.sbin/sendmail</filename> and is recommended - reading if you want to do any “tweaking” of your mail - setup.</para> - </sect2> - - <sect2> - <title>How can I do E-Mail with a dialup PPP host?</title> - - <para>You want to connect a FreeBSD box on a lan, to the Internet. The - FreeBSD box will be a mail gateway for the lan. The PPP connection is - non-dedicated.</para> - - <para>There are at least two way to do this.</para> + + <para>The sendmail FAQ is in + <filename>/usr/src/usr.sbin/sendmail</filename> and is + recommended reading if you want to do any + “tweaking” of your mail setup.</para> + </answer> + </qandaentry> + + <qandaentry> + <question> + <para>How can I do email with a dialup PPP host?</para> + </question> + + <answer> + <para>You want to connect a FreeBSD box on a lan, to the + Internet. The FreeBSD box will be a mail gateway for the lan. + The PPP connection is non-dedicated.</para> + + <para>There are at least two ways to do this.</para> - <para>The other is to use UUCP.</para> + <para>The other is to use UUCP.</para> - <para>The key is to get a Internet site to provide secondary MX services - for your domain. For example:</para> + <para>The key is to get a Internet site to provide secondary MX + service for your domain. For example:</para> - <programlisting> -bigco.com. MX 10 bigco.com. + <programlisting> +bigco.com. MX 10 bigco.com. MX 20 smalliap.com.</programlisting> - - <para>Only one host should be specified as the final recipient ( add - <literal>Cw bigco.com</literal> in - <filename>/etc/sendmail.cf</filename> on bigco.com).</para> - - <para>When the senders <command>sendmail</command> is trying to deliver - the mail it will try to connect to you over the modem link. It will - most likely time out because you are not online. - <command>sendmail</command> will automatically deliver it to the - secondary MX site, ie your Internet provider. The secondary MX site - will try every (<literal>sendmail_flags = "-bd -q15m"</literal> in - <filename>/etc/rc.conf</filename> ) 15 minutes to connect to your host - to deliver the mail to the primary MX site.</para> - - <para>You might want to use something like this as a login - script.</para> + + <para>Only one host should be specified as the final recipient + (add <literal>Cw bigco.com</literal> in + <filename>/etc/sendmail.cf</filename> on bigco.com).</para> + + <para>When the senders' <command>sendmail</command> is trying to + deliver the mail it will try to connect to you over the modem + link. It will most likely time out because you are not online. + <command>sendmail</command> will automatically deliver it to the + secondary MX site, i.e., your Internet provider. The secondary MX + site will try every + (<literal>sendmail_flags = “-bd -q15m”</literal> in + <filename>/etc/rc.conf</filename> ) 15 minutes to connect to + your host to deliver the mail to the primary MX site.</para> + + <para>You might want to use something like this as a login + script.</para> - <programlisting> + <programlisting> #!/bin/sh # Put me in /usr/local/bin/pppbigco ( sleep 60 ; /usr/sbin/sendmail -q ) & /usr/sbin/ppp -direct pppbigco</programlisting> - <para>If you are going to create a separate login script for a user you - could use <command>sendmail -qRbigco.com</command> instead in the - script above. This will force all mail in your queue for bigco.com to - be processed immediately.</para> - - <para>A further refinement of the situation is as follows.</para> - - <para>Message stolen from the freebsd-isp mailing list.</para> + <para>If you are going to create a separate login script for a + user you could use <command>sendmail -qRbigco.com</command> + instead in the script above. This will force all mail in your + queue for bigco.com to be processed immediately.</para> + + <para>A further refinement of the situation is as follows.</para> + + <para>Message stolen from the &a.isp;.</para> - <programlisting> + <programlisting> > we provide the secondary mx for a customer. The customer connects to > our services several times a day automatically to get the mails to > his primary mx (We do not call his site when a mail for his domains @@ -534,8 +282,8 @@ bigco.com. MX 10 bigco.com. > Is there a command that would initiate sendmail to send all the mails > now? The user has not root-privileges on our machine of course. -In the 'privacy flags' section of sendmail.cf, there is a definition -Opgoaway,restrictqrun +In the “privacy flags” section of sendmail.cf, there is a +definition Opgoaway,restrictqrun Remove restrictqrun to allow non-root users to start the queue processing. You might also like to rearrange the MXs. We are the 1st MX for our @@ -546,22 +294,191 @@ customers like this, and we have defined: OwTrue That way a remote site will deliver straight to you, without trying -the customer connection. You then send to your customer. Only works for -"hosts", so you need to get your customer to name their mail machine -"customer.com" as well as "hostname.customer.com" in the DNS. Just put -an A record in the DNS for "customer.com".</programlisting> - </sect2> +the customer connection. You then send to your customer. Only works for +“hosts”, so you need to get your customer to name their mail +machine “customer.com” as well as +“hostname.customer.com” in the DNS. Just put an A record in +the DNS for “customer.com”.</programlisting> + </answer> + </qandaentry> + </qandaset> </sect1> -</chapter> + + <sect1 id="mail-advanced"> + <title>Advanced Topics</title> -<!-- - Local Variables: - mode: sgml - sgml-declaration: "../chapter.decl" - sgml-indent-data: t - sgml-omittag: nil - sgml-always-quote-attributes: t - sgml-parent-document: ("../book.sgml" "part" "chapter") - End: ---> + <para>The following section covers more involved topics such as mail + configuration and setting up mail for your entire domain.</para> + + <sect2 id="mail-config"> + <title>Basic Configuration</title> + + <para>Out of the box, you should be able send email to external + hosts as long as you have set up + <filename>/etc/resolv.conf</filename> or are running your own + name server. If you would like to have mail for your host + delivered to that specific host, there are two methods:</para> + + <itemizedlist> + <listitem> + <para>Run your own name server and have your own domain. For + example, <hostid + role="domainname">FreeBSD.org</hostid></para> + </listitem> + + <listitem> + <para>Get mail delivered directly to your host. This is done by + delivering mail directly to the current DNS name for your + machine. For example, <hostid + role="fqdn">example.FreeBSD.org</hostid>.</para> + </listitem> + </itemizedlist> + + <para>Regardless of which of the above you choose, in order to have + mail delivered directly to your host, you must have a permanent + (static) IP address (no dynamic PPP dial-up). If you are behind a + firewall, it must pass SMTP traffic on to you. If you want to + receive mail at your host itself, you need to be sure of one of two + things:</para> + + <itemizedlist> + <listitem> + <para>Make sure that the MX record in your DNS points to your + host's IP address.</para> + </listitem> + + <listitem> + <para>Make sure there is no MX entry in your DNS for your + host.</para> + </listitem> + </itemizedlist> + + <para>Either of the above will allow you to receive mail directly at + your host.</para> + <para>Try this:</para> + + <screen>&prompt.root; <userinput>hostname</userinput> +example.FreeBSD.org +&prompt.root; <userinput>host example.FreeBSD.org</userinput> +example.FreeBSD.org has address 204.216.27.XX</screen> + + <para>If that is what you see, mail directly to + <email>yourlogin@example.FreeBSD.org</email> should work without + problems.</para> + + <para>If instead you see something like this:</para> + + <screen>&prompt.root; <userinput>host example.FreeBSD.org</userinput> +example.FreeBSD.org has address 204.216.27.XX +example.FreeBSD.org mail is handled (pri=10) by hub.FreeBSD.org</screen> + + <para>All mail sent to your host (<hostid + role="fqdn">example.FreeBSD.org</hostid> will end up being + collected on <hostid>hub</hostid> under the same username instead + of being sent directly to your host.</para> + + <para>The above information is handled by your DNS server. The DNS + record that carries mail routing information is the + <emphasis>M</emphasis>ail e<emphasis>X</emphasis>change entry. If + no MX record exists, mail will be delivered directly to the host by + way of its IP address.</para> + + <para>The MX entry for <hostid + role="fqdn">freefall.FreeBSD.org</hostid> at one time looked like + this:</para> + + <programlisting> +freefall MX 30 mail.crl.net +freefall MX 40 agora.rdrop.com +freefall MX 10 freefall.FreeBSD.org +freefall MX 20 who.cdrom.com</programlisting> + + <para>As you can see, <hostid>freefall</hostid> had many MX entries. + The lowest MX number is the host that ends up receiving the mail in + the end while the others will queue mail temporarily if + <hostid>freefall</hostid> is busy or down.</para> + + <para>Alternate MX sites should have separate Internet connections + from your own in order to be the most useful. Your ISP or other + friendly site should have no problem providing this service for + you.</para> + </sect2> + + <sect2 id="mail-domain"> + <title>Mail for your Domain</title> + + <para>In order to set up a “mailhost” (a.k.a., mail + server) you need to have any mail sent to various workstations + directed to it. Basically, you want to “hijack” any + mail for your domain (in this case <hostid + role="fqdn">*.FreeBSD.org</hostid>) and divert it to your mail + server so your users can check their mail via POP or directly on + the server.</para> + + <para>To make life easiest, a user account with the same + <emphasis>username</emphasis> should exist on both machines. Use + <command>adduser</command> to do this.</para> + + <para>The mailhost you will be using must be the designated mail + exchange for each workstation on the network. This is done in + your DNS configuration like so:</para> + + <programlisting> +example.FreeBSD.org A 204.216.27.XX ; Workstation + MX 10 hub.FreeBSD.org ; Mailhost</programlisting> + + <para>This will redirect mail for the workstation to the mailhost no + matter where the A record points. The mail is sent to the MX + host.</para> + + <para>You cannot do this yourself unless you are running a DNS + server. If you are not, or cannot, run your own DNS server, talk + to your ISP or whoever does your DNS for you.</para> + + <para>If you're doing virtual email hosting, the following + information will come in handy. For the sake of an example, we + will assume you have a customer with their own domain, in this + case <hostid role="domainname">customer1.org</hostid> and you want + all the mail for <hostid role="domainname">customer1.org</hostid> + sent to your mailhost, which is named <hostid + role="fqdn">mail.myhost.com</hostid>. The entry in your DNS + should look like this:</para> + + <programlisting> +customer1.org MX 10 mail.myhost.com</programlisting> + + <para>You do <emphasis>not</emphasis> need an A record if you only + want to handle email for the domain.</para> + + <note> + <para>Be aware that this means pinging <hostid + role="domainname">customer1.org</hostid> will not work unless + an A record exists for it.</para> + </note> + + <para>The last thing that you must do is tell + <application>sendmail</application> on your mailhost what domains + and/or hostnames it should be accepting mail for. There are a few + different ways this can be done. Either of the following will + work:</para> + + <itemizedlist> + <listitem> + <para>Add the hosts to your + <filename>/etc/sendmail.cw</filename> file if you are using the + <literal>FEATURE(use_cw_file)</literal>. If you are using + sendmail 8.10 or higher, the file is + <filename>/etc/mail/local-host-names</filename>.</para> + </listitem> + + <listitem> + <para>Add a <literal>Cwyour.host.com</literal> line to your + <filename>/etc/sendmail.cf</filename> or + <filename>/etc/mail/sendmail.cf</filename> if you are using + sendmail 8.10 or higher.</para> + </listitem> + </itemizedlist> + </sect2> + </sect1> +</chapter> |