On Wed, Jul 09, 2003 at 11:31:28PM -0400, Andrew Brown wrote:
> >> (3) sendmail example in /etc/defaults/rc.conf does work with the 
> >>     current sysinst, with some manual tweaking. 
> >
> >Except that all the sample sendmail config files are brain-dead.
> >In order to hide the machine name, and to put the correct address
> >in the envelope many systems will need:
> >	MASQUERADE_AS(`mydomain.com')
> >	FEATURE(`masquerade_envelope')
> >	FEATURE(`masquerade_entire_domain')
> >	FEATURE(`allmasquerade')
> >And if on dialup:
> >	CLIENT_OPTIONS(`Address=0.0.0.0, Modifiers=h')dnl
> >Indeed on dialup you may need to masquerade as a system in your ISPs
> >domain - and you definitely don't want that name escaping.
> 
> the default sendmail configuration assumes that a machine that is
> generating outbound smtp messages is properly configured to receive
> them at the same name.  if your host calls itself one thing, but is
> known in the dns as something else, or if you wish to use a third name
> for some reason, that's not "standard", and you can't expect not to
> have to do at least a little reconfiguration.

The above options are necessary for big corporate setups and for single
home systems - I've used them in both.

You need the masquerade options (mayby not quite all of them) in order
to remove the hostname from the mail addresses.  Most (sensible) large
organisations want email addresses to be name@company.com (or maybe
name@subdomain.company.com) but not name@machine.company.com.
(ie the name of the system where mail is read or written is not exposed
to the outside world.)

If you are sending mail over a dialup link, then the IP address of the
interface you are sending mail from, and hence its name, is not a constant.
So putting in the name of it's ethernet address is incorrect (read the RFC).
Unfortunately you can't get sendmail to use [nnn.nnn.nnn.nnn] system@domain
in the HELO/EHLO message, so you have to get it to put in the (unuseful)
dns name of the interface.
For this mail (probably) host213-122-33-103.in-addr.btopenworld.com

I'm not actually suggesting that this sendmail.cf file should be the default,
just that one of the examples should be like it.

	David

-- 
David Laight: david@l8s.co.uk