[ILUG] null client configuration for sendmail

[Badger]

On Wed, Aug 30, 2006 at 06:49:44AM +0530, Walter Faleiro wrote:
> On 8/30/06, Badger <badger at scattermail.com> wrote:
> >
> >On Tue, Aug 29, 2006 at 09:49:35PM +0530, Walter Faleiro wrote:
> >> Hi,
> >> I have a hostname fedora and my domainname is walter.com. The mail
> >server
> >> for our domain is server1.walter.com. When I try to send mails from my
> >linux
> >> system it goes as
> >>
> >> walter at fedora.walter.com.
> >>
> >> I can masquerade the same so that the email appears as walter at walter.com
> >.
> >>
> >> I need help in setting up the sendmail on my linux system "fedora" as a
> >null
> >> client.
> >>
> >> so mail peter
> >>
> >> Would send the mail to  peter at walter.com,  via our relay mail server
> >> server1.walter.com. Instead of sending it to peter at fedora.walter.com via
> >the
> >> local mail server.
> >>
> >>
> >> Regards,
> >> --Walter
> >
> >
> >There are a few things to note here.
> >
> >Probably best not to say "my domain is walter.com" unless it actually
> >is. The "example.com", "example.org" and "example.net" domains are
> >reserved specifically for example cases like this. For the rest of the
> >mail I'm going to assume that you used example.com because I don't
> >want to go making statements about some company's network in Quebec,
> >Canada.
> >
> >I don't actually use sendmail so be cautious about any advise I offer
> >about it.
> >
> >You can set up your host fedora.example.com as a nullclient using a
> >sendmail.mc that looks something like the following:
> >
> >   OSTYPE(`linux')
> >   FEATURE(`nullclient', `server1.example.com')
> >
> >However, I don't think that this is actually what you want. This
> >configuration is intended for a machine that does not accept it's own
> >mail: It basically says, "deliver all mail, no matter who it's for, to
> >server1.example.com". Think about the potential for mail loops here -
> >'all mail' means what it says on the tin.
> >
> >Such a configuration might be appropriate if you had an imap
> >server on server1.example.com which accepted mail for all users in
> >example.com. On a site where you wanted to relay mail out to hosts like
> >fedora.example.com you could possibly get this type of configuration to
> >work by abusing the EXPOSED_USER macro, but I certainly don't recommend
> >going this route.
> >
> >Personally, I would suggest going the route of setting up a shared
> >imap server on server1.example.com (or some other server), but if you
> >are adamant that you want mail delivered to many different hosts on your
> >network, then you might want to look into using a common mail aliases
> >database on each machine. That way each host would know that:
> >
> >   peter: peter at fedora.example.com
> >   leetgeek: leetgeek at gentoo.example.com
> >
> >For a large site with many hosts accepting mail you'll want to look into
> >LDAP (or failing that, NIS) to share this aliases database, but for a
> >small site you can just copy it out to the relevant hosts.
> >
> >- badge
> >--
> >Irish Linux Users' Group mailing list
> >About this list : http://mail.linux.ie/mailman/listinfo/ilug
> >Who we are : http://www.linux.ie/
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> >
> 
> Hi Badge,
> I am looking for the first solution
> 
> My sendmail.mc file looks something like
> 
> 
> divert(-1)dnl
> dnl #
> dnl # This is the sendmail macro config file for m4. If you make changes to
> dnl # /etc/mail/sendmail.mc, you will need to regenerate the
> dnl # /etc/mail/sendmail.cf file by confirming that the sendmail-cf package 
> is
> dnl # installed and then performing a
> dnl #
> dnl #     make -C /etc/mail
> dnl #
> include(`/usr/share/sendmail-cf/m4/cf.m4')dnl
> OSTYPE(`linux')dnl
> dnl # We're only a null client for the main mail server.
> FEATURE(`nullclient',`server1.example.com')dnl
> 
> But if I try to send the mail to peter it goes to
> peter at fedora.example.com and not as peter at example.com
> 
> Regards,
> --Walter
>

Now you are typing 'make -C /etc/mail' after you edit this file aren't 
you? :)

You also restarted the server, right? :)

Also a good idea to check your DNS to make sure it's all set up
correctly. Either you have set up the /etc/hosts file on
fedora.example.com to believe that 'example.com' points to
server1.example.com, or you have set up DNS with either an MX or 
an A record for 'example.com' which points to server1.example.com. 
Test this DNS stuff from the fedora.example.com host just in case 
your organization has some sort of split-DNS configuration.

Is this a fedora installation as it's hostname suggests? 
If so, is it Fedora 5?
If so, have you installed the sendmail-cf package?

I'm asking because I have a Fedora Core 5 box here and it took me just a
few minutes to set it up as a nullclient. If you have a similar set-up I
can list the steps I took so that you can see if there are any obvious
differences between what we have done.

- badge