Exim relaying and DNS questions (for small mail server)

[Rory Campbell-Lange <rory@campbell-lange.net>]

I've setup a machine in a little office to allow people in the office to
send each other email, and to download and parcel out incoming mail from
the isp using using fetchmail, exim and procmail. This all works fine.
The clients, all running macs, all can pick up pop3 mail served via
ipopd.

I'd like to be able to allow clients to send mail to other people on our
internal network, or to the isp, via the mail server. Clients presently
get a "relaying is denied" message from exim.

What I would like to do:

1.  Setup bind so that they can pickup and send mail via
    myname@mail.local.domain.com. I don't know the first thing about
    setting this up in small network. Pointers gratefully received.

2.  Fix the relaying issue
    I've read the "Control of Relaying" section in the exim docs.
    It appears that I need to:
    a)  set host_accept_relay to accept mail on
        192.168.181.0/255.255.255.0:localhost
    b)  set the local_domain so that local mail is put into local email
        boxes
        is localdomains = localhost:mail:192.168.181.0 ok here?
    c)  set a smarthost (the isp) who gets all the other mail
        authentication settings for _server side authentication_ (is
        this right, to allow client to attatch to this mail server).
        I can use the plaintext drivers to auth aagainst /etc/exim/passwd.
    Have I left anything out?

The network addresses are in the 192.168.181.0 range. The clients use
dhcp served from a mac softrouter/dhcp router connected to usb ADSL.
I've set the mail machine on a fixed ip on 192.168.181.20; the router is
on 192.168.181.254. The clients presently pick up mail using
myname@192.168.181.20.

-- 
Rory Campbell-Lange 
<rory@campbell-lange.net>
<www.campbell-lange.net>