but i want to use it in a commercial project really i won't need to pay??!!!
That depends a lot on what you mean by "commercial project".
For example if your "commercial project" is something along the lines of offering spam scanning services to users for a fee, ie: the way an ISP does, then you should be covered by the Apache license that comes with SA.
On the other hand if your commercial project involves trying to make a commercial spam scanning software package and sell that to people, but you want to steal some or all of the SA code to make it from, then you are probably not covered.
However, I'm not a lawyer, so, as Theo suggested, read the LICENSE and TRADEMARK files that come with SA. The Apache license is the license extended with the software.
