Relaxed Online Support Vector Machines (ROSVMs) have recently been proposed as an efficient methodology for attaining an approximate SVM solution for streaming data such as the online spam filtering task. Here, we apply ROSVMs in the TREC 2007 Spam filtering track and report results. In particular, we explore the effect of various slidingwindow sizes, trading off computation cost against classification performance with good results. We also test a variant of fixed-uncertainty sampling for Online Active Learning. The best results with this approach give classification performance near to that of the fully supervised approach while requiring only a small fraction of the examples to be labeled.