E-Mail Gateway

[Bart Silverstrim]

On Mar 8, 2004, at 11:25 AM, Wright, Greg wrote:

> I would like to use FreeBSD (4.9) as the platform on which to run an
> secure e-mail gateway.  At least that is what I think I would like to
> do.  The reason for FreeBSD is that I much more familiar with it than
> other "free" Unix like operating systems.  I have worked with DEC
> Ultrix, Digital Unix and AIX in the past so have some knowledge of 
> Unix.
>
>
> But the real goal is to put some sort of secure mail server/forwarder
> between my internal MS Exchange system and the Internet.  I don't want
> to connect Exchange directly to the Internet if at all possible.
>
> What I'm looking for are recommendations for "free" SMTP servers that I
> can use for this purpose.  I would like to include basic anti-virus and
> SPAM control as well.  Unfortunately, I have no money (other than my
> time) to do this project so am looking at minimal cost products.
>
> Any suggestions for e-mail gateways.  I've looked at postfix and qmail
> but am not sure that they are appropriate.  I could use the built in
> sendmail, but worry about security.

I'm in the middle of this kind of project right now.

Using
postfix-SMTP server
clamav-free antivirus
amavisd-new-plugin daemon that redirects mail to spamassassin and the 
clamd antivirus for checking

Mail comes in, gets checked for viruses, and then checked and scored as 
spam.  Quarantines things that don't pass, forwards everything else to 
our internal Exchange server.  Postfix is a good choice for me; it's a 
drop in replacement for sendmail and tends to be simpler to configure.  
All absolutely free...we only paid for the server hardware to do this.

-Bart