site hiding and other stuff

[Adam Bentley]

Hi there,
here I go again, yet more questions for you sendmail bods out there!

Here's what I want to do :

A user comes along and says that he wants to receive and
send email directly from his unix box, from within and also
outside the polytechnic; in fact lots of users would like to
do this, but I don't really want to start registering all
these people's machines in the NRS.

What I thought about was simply setting up an alias for
each user on our mailhub like

joe:joe@unixbox

so that mail sent to j...@uk.ac.coventry would go to joe
on his machine. I guess I can make sendmail just attempt
smtp connections to the specified hostname in the alias
file and thus deliver the message.

But when joe@unixbox replies to the message, how can I make
the message

1. Go back to the mailhub rather than extern...@uk.ac.somewhereelse
2. Rewrite the message headers so that From: contains j...@uk.ac.coventry
instead of joe@unixbox so that externaluser can still reply sucessfully?

I am running UK-Sendmail 2.1 on Sequent Symmetry S81.

Any thoughts? Does anyone else do this kind of thing?

thanks for any info.
--
_
/-\dam

FLESH: Adam Bentley (Fraggle), Programmer/Adviser, Systems, Coventry Poly. UK
INET : ad...@cck.cov.ac.uk

[Frederick M. Avolio]

We do some of this here. Suggestion 1 -- check out decuac.dec.com,
pub/sendmail-cf/generic.cf. Suggestion 2 -- there will be a pre symposium
seminar on this very subject at the May US DECUS.

Fred

[T.D...@durham.ac.uk]

Re:

See the JNT's "Network News" Number 30 (Dec 1989) for the article
"Centralised Electronic Mail -- The Newcastle Experience".

This describes how both Durham and Newcastle handle e-mail
(see my e-mail address for example) using a central directory
of all mail users and without involving any "alias" file changes
on any of the (many) end systems.

Outgoing mail leaves a machines signed "identifier@machine" and
is sent to the mail hub (we have appropriate "sendmail.cf" files).
The hub re-signs it "A.B....@uk.ac.durham" and sends it out
into the wide world.

Incoming mail for "A.B....@uk.ac.durham" arrives at the mail hub
which determines where to send it: "identifier@machine".

All incoming mail is sent to one place, but mail may optionally be sent
from additional places.

It seems to work very well in practice (but then I'm biased) and could
put you in a good position to move from sendmail to PP (at least I hope
so; that is our firm intention and the JNT gave us a machine for it!).

On the hub itself, you will need "IDA-sendmail" rather than neat "sendmail",
to handle the "dbm" lookups in the user directory.

Give me a ring (rather than e-mail) if you want to discuss it some more.


: David Lee Computer Centre :
: University of Durham :
: Phone: +44 91 374 2882 (ddi) South Road :
: Fax: +44 91 374 3741 Durham :
: ARPA: T.D...@durham.ac.uk U.K. :
: JANET: T.D...@uk.ac.durham :