The interactive gateway system for countering spam is a general interactive mechanism for countering various inter-domain spam messages@ including e-mail spam@ SMS spam@ etc.@ to enable information sharing for countering spam among different domains@ and to prevent spam from being sent as well as from being received. This Recommendation supports the diversity of spam-countering filtering techniques@ and offers flexibility for upcoming techniques. Compliance with all relevant national laws and regulations should be considered before adopting this Recommendation.