I'm a newbie to spamassassin

[Xavi Montero <xm...@dsitelecom.com>]

Hello to everybody.

I've been trying to get Spamassassin + razor working but I'm a bit lost 
at linking spamassassin to the MTA.
I've tried the documentation on the website, but it is a bit confusing 
for me. Perhaps too much information?
I've tried the FAQ but I'm not able to find my answer.

SITUATION:

- Debian, stable. Sources.list =
deb http://www.backports.org/debian/ woody spamassassin razor clamav 
openldap2 amavisd-new
deb http://http.us.debian.org/debian stable main contrib non-free
deb http://non-us.debian.org/debian-non-US stable/non-US main contrib 
non-free
deb http://security.debian.org stable/updates main contrib non-free

- MTA = Sendmail (currently the loaded stable version is 8.12.3-7.1)

* I'm trying to get rid of the spam
* I manage a server which collects mails for several domains
* I want a server-wide spam filter (not just one user, but all the users)
* But I want user-based, easy-to-admin white lists or black lists (only 
if possible, not a requisite)
* I want auto-updateing rules (razor?)
* If possible, I prefer to use dselect for installing compiled packages 
and do not compile anything by hand (for maintainance reasons).
* I'm currently running another sendmail filter: Clamav antivirus 
filter. It runs properly.

Installed software (related to this subject):

sendmail     8.12.3-7.1 
clamav-milter 0.75.1-1.backports
libclamav1   0.75.1-1.backports
clamav       0.75.1-1.backports
clamav-base  0.75.1-1.backports
clamav-daemo 0.75.1-1.backports
clamav-fresh 0.75.1-1.backports
clamav-testf 0.75.1-1.backports
maildrop     1.3.7-2
spamassassin 3.0.0-0.backports
spamc        3.0.0-0.backports
razor        2.610-1.backports
libmilter-dev 8.12.3-7.1

Note: Clamav is running perfect. I pursue the same behaviour on 
spamassassin.

QUESTIONS:

I think I have everything installed, except, perhaps, the "glue" between 
spamassassin and sendmail. I guess that the glue can be "several 
things", one of those being a "milter". I've read that a "milter" can be 
used. But I cannot guess the answer to the following questions:

1) What exactly is a milter (appart from a "mail filter")? Do milters 
work only on sendmail or on any MTA?
2) Do I need a milter? Or there is an easier way to do that?
3) Is there EXACTLY one milter that links one app to sendmail? or One 
application may be linked to sendmail thru SEVERAL milters and you 
choose one of those?
4) If so, which is the criteria to choose one milter or another for a 
given app? (In this case how do I choose a milter for spamassassin?)
5) Do all milters behave equally from the point of view of the app? I 
mean: For spamassassin to use a milter... does the milter need to be 
prepared to "link" to spamassassin? Or spamassassin should link to ANY 
milter available regardless of the milter is aware or not taht 
spamassassin exists?
6) In any case: Does clamav-milter support spamassassin? Or only clamav?
7) If not... Is there a milter that links both clamav and spamassassin? 
Or I must use a separate milter for each?

Sorry if those questions are too obvious to all you, but I'm completely 
lost - I'm unable to digest all the info available on the web. If you 
can help me to find out if I need a milter or not, and if so, which 
milter do I need, I'll continue with more questions :-)

Thanks VERY much in advance.
Xavi.