From bret_stern at machinemanagement.com  Mon Mar  7 18:55:31 2011
From: bret_stern at machinemanagement.com (Bret Stern)
Date: Mon, 07 Mar 2011 10:55:31 -0800
Subject: Sendmail/Spamassasin/Spam
Message-ID: <1299524131.4953.18.camel@fedora13>

Hey,

I'm hosted on Verio VPS Red Hat Enterprise 3.

Haven't spent a lot of time with Sendmail, but i'm getting
pissed with all the spam, and probably need a basic understanding
of the mail services.

Using:
Sendmail 8.14.4
SpamAssassin

Can I setup (similar to IPTABLES), reject all mail
except from specific domains using the access db?

I've seen some samples, but not specifically what I want to do....
or is this not a good idea.

As always, thanks.





From ricks at nerd.com  Mon Mar  7 19:18:58 2011
From: ricks at nerd.com (Rick Stevens)
Date: Mon, 07 Mar 2011 11:18:58 -0800
Subject: Sendmail/Spamassasin/Spam
In-Reply-To: <1299524131.4953.18.camel@fedora13>
References: <1299524131.4953.18.camel@fedora13>
Message-ID: <4D752FA2.3070604@nerd.com>

On 03/07/2011 10:55 AM, Bret Stern wrote:
> Hey,
>
> I'm hosted on Verio VPS Red Hat Enterprise 3.

RHEL3?  Geeze!  That went end-of-life a LONG time ago!

> Haven't spent a lot of time with Sendmail, but i'm getting
> pissed with all the spam, and probably need a basic understanding
> of the mail services.
>
> Using:
> Sendmail 8.14.4
> SpamAssassin
>
> Can I setup (similar to IPTABLES), reject all mail
> except from specific domains using the access db?
>
> I've seen some samples, but not specifically what I want to do....
> or is this not a good idea.

What you're asking to do is a "whitelist" (a list of servers or domains
allowed to send mail to you).  This can be become difficult to support--
depending on how big your whitelist will be.  Alternately, you can
subscribe to a "blacklist" such as spamhaus to block known spammers.
In other words, as long as the sender isn't on spamhaus' list, they can
send you mail.

I'd suggest googling whitelist and blacklist and reading those articles.
There's also good articles on using things like Spamassasin and other
filters (lookup "sendmail-milters").

Also note that sendmail can be a right bitch to manage.  You might be 
better off with postfix.  Much easier to manage, if not as flexible as
sendmail.  It's really easy to shoot oneself in the foot with sendmail.
----------------------------------------------------------------------
- Rick Stevens, Systems Engineer, C2 Hosting          ricks at nerd.com -
- AIM/Skype: therps2        ICQ: 22643734            Yahoo: origrps2 -
-                                                                    -
-          "How does that damned three seashell thing work?"         -
-                           - Sylvester Stallone, "Demolition Man"   -
----------------------------------------------------------------------



From immortal at nwconx.net  Tue Mar  8 06:37:08 2011
From: immortal at nwconx.net (Tim Thorburn)
Date: Tue, 08 Mar 2011 01:37:08 -0500
Subject: Sendmail/Spamassasin/Spam
In-Reply-To: <1299524131.4953.18.camel@fedora13>
References: <1299524131.4953.18.camel@fedora13>
Message-ID: <4D75CE94.8070508@nwconx.net>

On 3/7/2011 1:55 PM, Bret Stern wrote:
> Hey,
>
> I'm hosted on Verio VPS Red Hat Enterprise 3.
>
> Haven't spent a lot of time with Sendmail, but i'm getting
> pissed with all the spam, and probably need a basic understanding
> of the mail services.
>
> Using:
> Sendmail 8.14.4
> SpamAssassin
>
> Can I setup (similar to IPTABLES), reject all mail
> except from specific domains using the access db?
>
> I've seen some samples, but not specifically what I want to do....
> or is this not a good idea.
>
> As always, thanks.
Check out some of the RBL's you can install using the vinstall command.  
I believe most VPS' came preinstalled with at least one RBL, however you 
can install a number of additional lists.  You could also try adjusting 
SpamAssassin sensitivity to handle some of the spam.  Not sure how the 
newer cpanel VPS servers handle the spam issue.

-Tim