Spamassassin Users - Adding Rulesets

[Matt Florido]

New to Ubuntu and I have a couple of quick questions for Spamassassin
users.  I noticed out of the box, Spamassassin attaches a summary log of
its scan results on a particular email.  Cool feature.  However, I'm
wondering if it's safe to run sa-learn with this additional attachment,
or if I need to remove them first?  Here's an example:

 pts rule name              description
---- ----------------------
--------------------------------------------------
 1.2 SPF_NEUTRAL            SPF: sender does not match SPF record
(neutral)
 2.0 SPF_HELO_NEUTRAL       SPF: HELO does not match SPF record
(neutral)
 2.4 TVD_FW_GRAPHIC_NAME_LONG BODY: TVD_FW_GRAPHIC_NAME_LONG
 2.2 HTML_IMAGE_ONLY_24     BODY: HTML: images with 2000-2400 bytes of
[snip...]

Secondly, is it necessary to download rulesets from rulesemporium, or
does the SA package that comes with Ubuntu sufficient?  If I can add my
own rules, do I just simply place them in /etc/spamassassin??

I know I can ask these questions in the SA list, but I thought I would
ask this list first since it may be Ubuntu specific.

Thanks!

-- 
Regards,
Matt Florido