Re: This is WAY off topic, but...

[Brian Stafford <brian stafford uklinux net>]

On Tue, 18 September 02:58 Raven wrote:
> ...how do you set up a mail server that receives mail from the Internet and
> distributes it to users on an internal net?

Hmmmm... tricky.

> I have:
> 	1) a static IP
> 	2) a domain name registered (ravenslakeconsulting.com)
> 	3) an internal net, using IP-MASQ successfully.
> 	4) and enough firewall to keep things calm, mischief-wise.

The most preferred (i.e. lowest numbered) MX record must refer to the host
on your fixed IP address.  MX records may only refer to publicly addressed
MTAs, that is an MTA which is accessible on port 25 from anywhere on the
internet.

Note on MX routing; when locating an MTA which will accept a message, the
most preferred records are tried first, then the sending host will fallback
to less preferred MX hosts until the message is sucessfully transferred.
If an MX record for the delivery domain refers to the local host, it will
never attempt to relay the message to another host with an equal or less
preferred MX for the same delivery domain.  A message will therefore either
always move "nearer" the final destination in as few hops as possible
or stay where it is if none of the more preferred hosts are on line.

When your local MTA identifies incoming mail as belonging to its
domain (RHS of mailbox address), it will use the LHS of the mailbox address
to route the message to its final destination.  How that mapping is done
depends on your MTA.  Presuming the MTA will have access to host names on your
internal network (/etc/hosts or DNS), you could set up aliases to map the
mailboxes to varoius hosts on the local network.  (Word of advice - don't
use sendmail unless you are a masochist.)

My personal feeling is that routing mail internally via SMTP on a small local
network is more bother than its worth.  I'd set up an IMAP server on the
publicly
accessible host, have the MTA deliver to that and point the UAs at the IMAP
server.  The UAs can always save the message locally if necessary.  The IMAP
server need not be configured for the public IP address - just the private one.

Brian Stafford