In a method for controlling the delivery of short text messages or other messages in a wireless network, a source terminal transmits a message to a recipient wireless unit over the network's short messaging service (“SMS”). The message includes a message identifier, a communication identifier of the recipient wireless unit, and message content. Initially, it is determined whether the message satisfies a criterion for blocking the message. If so, the message is blocked. For example, transmission of the message may be blocked if the message identifier is not an authorized identifier. Alternatively, the message may be blocked if the message identifier is an unauthorized identifier. This may be determined by cross-referencing the message identifier to an identifier record of the wireless unit. The identifier record is a data entry, list, or other record associated with the wireless unit for purposes of screening/blocking messages.