Here's an example of the header I got on one message:

SPAM: ---- Start SpamAssassin results

SPAM: 16.00 hits, 9 required;

SPAM: * -2.8 -- Where are you working at?

SPAM: *  3.3 -- Subject contains "FREE" in CAPS

SPAM: * -0.5 -- BODY: Offers a limited time offer

SPAM: *  2.8 -- BODY: No such thing as a free lunch (2)

SPAM: *  2.6 -- BODY: Claims you can be removed from the list

SPAM: *  1.9 -- BODY: Claims you can be removed from the list

SPAM: *  1.7 -- BODY: List removal information

SPAM: *  1.6 -- BODY: Free Offer

SPAM: *  1.2 -- BODY: Save Up To

SPAM: *  1.1 -- BODY: Save big money

SPAM: *  0.3 -- BODY: While Supplies Last

SPAM: * -0.4 -- BODY: FONT Size +2 and up or 3 and up

SPAM: * -0.1 -- BODY: Spam phrases score is 08 to 13 (medium)

SPAM:           [score: 11]

SPAM: *  1.4 -- RAW: Message text in HTML without specified charset

SPAM: *  1.3 -- Subject is all capitals

SPAM: *  0.2 -- 'Message-Id' was added by a relay (3)

SPAM: *  0.4 -- Subject has lots of exclamation marks

SPAM:

SPAM: ---- End of SpamAssassin results