Sendmail restrictions and frontends

[Daniel McNamara]

Hi guys,

I've got a bit of a problem that's driving me insane. I have been asked to
set up a sendmail server in the office which is to handle outgoing mail
only. So it's to be a relay only server. Using the /etc/mail/access database
I've locked down which IP can use the server for outgoing relay but my
bosses want me to take it one step further.

They also want a check in place that checks the "From" field from users
within our IP range so that only email that says that it's from one our
domains will be relayed through. So basically:

User from IP range can send mail as if from joe at domain-we-own.com but NOT
joe at aol.com

We have this set up already using a commercial NT mail server but due to
crippling licensing costs the bosses want to move to more open source
initiatives, however without this feature they won't even consider it. I'm
pretty sure it can be done (I'll be very surprised if it can't) however I'm
having huge difficulties in figuring out exactly how to do it. I've
attempted to read a lot of sendmail doco but I can not understand a lot of
it and since I'm not sure what I'm looking for I could be looking in
completely the wrong places. Has anyone out there had to set up anything
like this? Or at least have any idea on I would start looking?

On another topic another requirement to getting this machine of the ground
is that I need to have an easy to use click n drool GUI (web based is fine)
for the bosses to use to control the sendmail server (mostly just to
add/remove from the lists of allowed relay domains). So far I've tried
playing with Webmin but I can not seem to get it to do what I want not to
mention documentation for Webmin is just about non-existent. Any other
systems that people are aware of that is easy to set up and maintain? Or at
least how to use Webmin for the purpose outlined above?

I am using Red Hat 7.2 which has sendmail 8.11.6-3 installed. I would prefer
to learn how to hack the m4 files myself for any initial set-up rather than
use tools such as linuxconf. Also if anyone thinks it would be easier to use
a different MTA I am more than open to suggestion. At this point in time any
ideas would be good.

Any help would be great

Cheers

Daniel