I am a fairly new user, but my IP should certainly be clean from Spam.
Unless you yourself are a Tier1 ISP or have a permanently static address*, you're probably sharing your IP address with a bunch of other people (e.g. bots, spammers, and the unsuspecting hosts to these techniques).
(*even in this instance you could be at the mercy of the ISP sharing you all through a proxy, or of PPRuNe deciding that on an IP range policy).