sendmail

[Jim Reid]

>>>>> "John" == John Thayer Jensen <j.jensen at auckland.ac.nz> writes:

    >>  Well the obvious thing to do is make an entry for
    >> linux1.harts.co.nz in the DNS. If this is the name your mail
    >> software uses when it tries to find a local SMTP server, then
    >> that name has to be in the DNS!

    John>      Maybe I didn't explain enough.  That machine is not on
    John> the Internet.  It is just on my internal network and has an
    John> IP of 10.0.0.1.  It dials up to my ISP.  I suppose I could
    John> ask my ISP to make a DNS entry, but it's not going to be
    John> receiving mail, not now, so I suppose its MX record would be
    John> that of my ISP.  BTW, when it does a PPP connexion via my
    John> ISP, of course it gets a real IP address for the duration of
    John> that session, but it's dynamic, not always the same address.

Yes, you should have mentioned this at the outset. It puts a different
perspective on things. What you have to do depends on how you want
mail to work. Do you want outgoing mail to be queued on the Linux box
and only sent whenever the PPP link is up or do you want outgoing mail
to be sent immediately by bring up the dial-up line and speaking SMTP
to your ISP's mail relay? And will your incoming mail be queued at
that relay or will the ISP host your mailboxes? Most of the work will
be in configuring sendmail. You'll probably want to configure and run
a name server for your zones on the Linux box so that sendmail can do
the Right Thing with local mail whether the PPP link is up or not.

And if there are other network services on this box - like a web
server or web proxy - these may also have an impact on how the DNS has
to be configured.