[thelist] repost: linux and exchange spam solution

[Chris W. Parker]

seeing that everyone (afaik) is back from their christmas vacations i am
reposting this email i sent when traffic was very low on thelist.
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hi.

i've been toying with using sendmail/spamassassin on a linux box placed
in front of our exchange server to do our spam filtering.

i've received some very helpful help (a bit redundant?) from a listee
member. however instead of continuously bugging him, i thought i'd come
to the list for some ideas and maybe some pointers.

what i've done so far is take a computer home from work (an old hp
that's been lying around) and set it up on my home network which is
connected to teh intarweb via dsl. (the member i spoke about earlier
even went so far as to give me a temporary domain for testing purposes.)
i've got redhat 8 installed with sendmail and spamassassin working
properly.

here are my problems.

1. i'm not sure what DNS changes need to be made at our isp (earthlink)
so that i can properly integrate the computer for testing purposes
and/or production. i'm confused by the whole MX record thing. let me
explain why i'm confused...

our domain for this example will be domain.com (how original!). that
makes our webserver at domain.com and www.domain.com, our email server
(the exchange 2k box) is at mail.domain.com.

when someone sends mail to user at domain.com (somewhere along the line) it
is found out that mail should be directed to the computer lying at
mail.domain.com correct?

if that is the case (which indeed i believe it is) what would i need to
change to have the mail be sent to the linux box? would i need to
register the linux box as mail.domain.com and make the exchange box
something else, like exchange.domain.com?


2. i've been using the virtusertable file to forward mail while i've
been making my tests. however this has the unfortunate side affect of
changing destination domains. for example if i send an email to
chris at mytestdomain.friend.com i can forward it to my hotmail address.
what i found out later is that i need to use the mailertable instead of
the virtusertable to avoid this problem. however i can't seem to do this
because i think the DNS records need to be setup properly first.


having said all that, i'd appreciate any links/hints/help that you could
offer me while i try to get this thing done.


thanks a lot!!!

chris.