I installed SME Server 7 as an upgrade to an unmodified SME 6.5 rc 1. Spamassasin was working before the upgrade. Now the init fails saying the server port is "in use".
I had this problem too. So far as I can see, it does not have a detrimental effect, but is annoying none-the-less.
In my case, it was because spamassain was proviously installed (using the Knudsen scripts). I removed the rpms, but they leave behind a few strands that cause this error.
Under /etc/rc1.d/ to /etc/rc7.d/ there are entries for spamassin as well as spamd. The SME 7 daemon is 'spamd' and the older daemons are 'spamassassin'. Remove the latter from those directories, mostly K60spamassassin, and the error goes away.
Obviously back up what you do delete, just in case there is something I have overlooked, but this does appear to be working for me so far.
-- Jason