Sendmail/Spamassasin/Spam

[Rick Stevens]

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"   -
----------------------------------------------------------------------