A message distribution center (MDC) and Intelligent Delivery Agent in a wireless Internet gateway interposed between content providers and a wireless carrier to subjectively examine and direct messages via simple mail transfer protocol (SMTP) based on desired rules using standard SMTP Gateway and other known protocols. The MDC includes an individual queue for each subscriber, and the provider is informed through conventional SMTP messages that the short message has been accepted. If the carrier has specifically disallowed service for a particular mobile identification number (MIN), then the content provider is informed that the recipient is invalid. An MDC provides a single mechanism for interacting with subscribers of multiple carriers, regardless of each carrier's underlying infrastructure. An MDC protects networks by intelligently throttling messages and configuring message delivery parameters. An MDC receives presence information. A content provider communicates with the MDC using SMTP messages, and the MDC communicates with wireless carriers.