What is this test: MISSING_SUBJECT 1.40 Missing Subject: header
The above test is for this header:
Todd's comments about RM being a marketing company noted, but also RM's relatively clean reputation on NANAE, and claimed strong antispam policies, I'll answer anyway. (http://www.realmagnet.com/antiSpam.html)
I'd try running the message through spamassassin -D. Odds are pretty good that although there appears to be a "Subject" header, there's some broken insertion of linefeeds elsewhere in the headers which is making SA think that it's part of the body text. (There should be no blank lines in the headers. Make sure to check for one before the first header as well...)
Either that or the linefeed format on the header preceding the subject is wrong (ie: bare CR or bare LF instead of CR LF) or missing.
Many mail clients are "understanding" of these errors due to lax parsing and wind up finding the subject line anyway. SA's parsing is lax in some respects, but not everywhere.
