SURBL filtering, Bayesian Analysis and heuristics are techniques used to ensure spam filters offer up-to-date protections and do not rely on historical blacklists to identify spam. SURBL filtering uses real time blacklists of IP addresses known to be associated with spam emails, and quarantines messages based on these addresses. Bayesian Analysis uses statistical techniques and Machine Learning to identify unusual word patterns or spellings that may be used to circumvent inbuilt spam filters (such as “Prize” being spelt as “Pr!ze”). Heuristic algorithms scan emails based on pre-configured rules that help to determine the probability of an email being spam in the quickest possible time.