Mail2News Mini-Howto <author>Robert Hart, InterWeft IT Consultants Melbourne, Australia <tt/iweft@ipax.com.au/ <date>v1.0, 4 November 1996 <abstract> This document describes how to set up your news server and the mail2news.pl software to link mailing lists to local news groups. </abstract>  <sect>Copyright and such The copyright of this document is retained by the author. Permission is granted to distribute the document by electronic means and on CDs provided that it is kept entirely in its original format. Permission is also granted to print a copy of this document for personal use. The republishing of this document in part or in whole without the permission of the copyright holder by any means other than as noted above is prohibited. This document is directly supported by InterWeft IT Consultants (Melbourne, Australia). The latest version of this document is available at the InterWeft WWW site at <url url="http://203.29.72.65/" name="InterWeft IT Consultants">. <sect>Introduction Most Internet sites are always seeking ways to improve the usage of the limited bandwidth awailable across their link to the Internet. Should more than one user subscribe to the same mailing list, there is going to be traffic duplication. If there are a number of such duplications - or the traffic on the lists is high, the consumption of bandwidth increases. By subscribing the <bf/site/ to a list (if this is allowed by the list owner) and 'gating' the email traffic to the local news server, it is possible to make mailing lists accessible to all site users, or, using the security features of 'innd', to limit the access to certain users. Such a site subscription (particularly if there are a number of high traffic lists) can make worthwhile savings in bandwidth usage. Reading list traffic in news reader also offers users the advantages of threading (which is not available in many mail user agents) and keeps their mail 'inbox' free for possibly more urgent, personal email. This mini-HOWTO describes setting up the 'mail2news.pl' script to accomplish this. <sect1>Finding mail2news.pl The author has been unable to find mail2news.pl on CPAN (the Comprehensive Perl Archive Network) - but it may just have been overlooked. It is however on sunsite.unc.edu - somewhere - and also on ftp.redhat.com. As this Perl script is not lengthy, it is appended to this howto. <sect>Overview of the system It is probably easiest to understand how this system works by tracking a message from the mailing list to the newsgroup and then a message posted to the local newsgroup (gated to the mailing list) and see how they are handled. <sect1>Mail from the mailing list Mail from the mailing list is sent to all subscribed mail addresses. A special mail alias is subscribed to the mailing list in question and so all traffic to and from the list is sent by the list server to this address. When mail from the mailing list arrives at the local machine, the mail alias pipes the incoming message to <tt/mail2news.pl/. The mail alias also specifies the destination (local) newsgroup. The <tt/mail2news.pl/ script processes the message, applying news headers and then uses <tt/rnews/ or <tt/inews/ to post the message to the newsgroup. <sect1>Messages posted to the local newsgroup The local newsgroup is set up as a <bf/moderated/ group, as this allows us to take advantage of the email capabilities of innd. Any messages posted to a moderated group are <bf/not/ immediately submitted to the group. Instead, messages are emailed to the moderator of the group. By declaring the moderator of the local newsgroup to be mailing list address, all locally posted messages to the newsgroup are automatically mailed out to the mailing list by <tt/innd/ and <bf/only/ appear once they have been received back through <tt/mail2news.pl/ which adds the necessary 'approved' line to the messages and are thus acceptable to innd for posting to the newsgroup. <sect>Setting up mail2news Put the <tt/mail2news.pl/ script in a suitable location. I favour <tt>/usr/local/scripts</tt>, but the location is up to you. You will need to edit script as follows:- <itemize> <item>At the top of the script, make sure you are pointing at the local Perl binary <code> #!/usr/bin/perl # point at the correct location of perl </code> <item>I had problems with the three following lines. Commenting them out does not cause a problem. <code> ( $version ) = $] =~ /(\d+\.\d+).*\nPatch level/; die "$program: requires at least version 3 of perl\n" if $version < 3; </code> <item>Edit the following lines to point at the posting program (I use rnews) and you news host:- <code> # $inews = "/usr/bin/inews"; # $iopts = "-h -o \"mail2news gateway\""; $inews = "/usr/bin/rnews"; $iopts = ""; $postinghost = "your.news.server"; # points at your news server </code> <item>Make sure that the script is exectuable (mode 755). </itemize> <sect>Establishing the mail aliases Edit <tt>/etc/aliases</tt> to create entries for the mailing list(s) you wish to pipe into news. Each entry should be of the form:- <code> <subscribed email address to list>: \ "| /usr/local/scripts/mail2news.pl <local news group name>" <code> So for example if the email address to which email from the list is to be sent (the subscribed mail address) is <tt/site_list/ and the local newsgroup to which mail is to be posted is <tt/local.site.group/, the alias would be <code> # The site subscription address for blah-blah@some.mailing.list site_list: "| /usr/local/scripts/mail2news.pl local.site.group" </code> Make an entry for each mailing list that is to be gated to oyur local news server and and then run newaliases. <sect>Setting up the news groups and news server (innd) Using <tt/ctlinnd/, create the newsgroups on your news server. Remember, these are to be <bf/local/ news groups, so start them with a distinctive name so you can filter them out from your news distributions (in your <tt/newsfeeds/ file). You also need to tell <tt/innd/ that the group is moderated (by using ctlinnd). Remember, <tt/innd/ is <bf/very/ sensitive to file ownership and permissions, so you need to interct at this level with <tt/innd/ as the <tt/news/ user. Indicating a moderated group is done by specifying <tt/m/ to the <tt/newgroup/ command. <code> ctlinnd newgroup <newgroup name> m <newsadmin> </code> The <bf><tt/m/</bf> tells <tt/innd/ that the group is moderated. Edit your newsfeeds file to make sure that these local groups are <bf/not/ distributed (unless you specificaly wish this to occur). For example, if your mailing list is called <tt/local.site.group/, then you would probably want to add <tt/!local*/ to the second field of your up (and possibly your down) stream news sites in your <tt/newsfeeds/ file. Now, in order to ensure that user messages are sent to the list automatically by innd, edit <tt>/etc/news/moderators</tt> to include a line declaring the mailing list email address as the moderator. <code> some.site.list:list@mail.list.site </code> <sect>Subscribing the mail2 news alias to the mailing list You now need to subscribe the mail alias to the mailing list. Check with the mailing list information as to how to subscribe. Some mailing lists allow you to subscribe an email address that is different from the address from which the subscription comes (they check back to the address to be subscribed for confirmation before actually subscribing that address). Other mailing lists do not permit this. So you may need to 'forge' a subscription request. There are many ways of doing this. One of the easiest is to use Netscape mail set up (temporarily) with the address to which the mailing list is to send the mail. After subscribing, you should see a 'welcome' message of some kind from the list server in the news group - in which case all is well and you can now test the other direction by posting a news message to your new list. The message should <bf/*NOT*/ appear in the newsgroup at once. It should get sent out by mail and then received back and posted to the news group. If this works, you have succeed in getting the list gated to news. <sect>If it doesn't work... If things don't work, you need to track through the path the messages are taking to see exactly where things are breaking down. Useful tools here are the mail and news logs. <bf/Robert Hart/<newline> Melbourne, Victoria, Australia October 1996 <sect>The mail2news.pl script <code> #!/usr/bin/perl ($program = $0) =~ s%.*/%%; #( $version ) = $] =~ /(\d+\.\d+).*\nPatch level/; #die "$program: requires at least version 3 of perl\n" # if $version < 3; # $inews = "/usr/bin/inews"; # $iopts = "-h -o \"mail2news gateway\""; $inews = "/usr/bin/rnews"; $iopts = ""; $postinghost = "your.news.server"; if ($#ARGV < 0) { # $newsgroup = "test"; # we'll expect the newsgroup line in the body } elsif ($#ARGV == 0) { $newsgroup = $ARGV[0]; } else { die "usage: $program [newsgroup]\n"; } # in case inews dumps core or something crazy $SIG{'PIPE'} = "plumber"; sub plumber { die "$program: \"$inews\" died prematurely!\n"; } open (INEWS, "| $inews $iopts") || die "$program: can't run $inews\n"; # header munging loop while (<STDIN>) { last if /^$/; # transform real from: line back to icky style s/^From:\s+(.*) <(.*)>/From: $2 ($1)/; s/Message-Id/Message-ID/; # transform from_ line to path header; also works locally s/^From\s+(\S+)@(\S+).*/Path: $2!$1/ || s/^From\s+(\S+)[^@]*$/Path: $1\n/; print INEWS # if /^(Date|From|Subject|Path|Newsgroups|Organization|Message-ID):/i; if /^(Date|From|Subject|Path|Newsgroups|Message-ID):/i; $saw_subject |= ( $+ eq 'Subject' ); $saw_msgid |= ( $+ eq 'Message-ID' ); # $saw_newsgroup |= ( $+ eq 'Newsgroups' ); } warn "$program: didn't expect newsgroup in both headers and ARGV\n" if $newsgroup && $saw_newsgroup; die "$program: didn't get newsgroup from either headers or ARGV\n" unless $newsgroup || $saw_newsgroup; $approved = $newsgroup; $approved =~ s/\./'-'/eg; ($sec,$min,$hour,$mday,$mon,$year)=localtime(time); $madeupid = "\<$year$mon$mday.$hour$min$sec.$$\@kepler.hedland.edu.au\>"; printf INEWS "Newsgroups: %s\n", $newsgroup if $newsgroup; printf INEWS "Approved: %s\@kepler.hedland.edu.au\n", $approved; print INEWS "Subject: Untitled\n" unless $saw_subject; printf INEWS "Message-ID: %s\n", $madeupid unless $saw_msgid; printf INEWS "NNTP-Posting-Host: %s\n", $postinghost; print INEWS "Organisation: (mail2news gateway)\n"; print INEWS "\n"; print INEWS while <STDIN>; # gobble rest of message close INEWS; exit $?; </code> </article>