Aspects of the disclosure relate to identifying potentially malicious messages and generating instream alerts based on real-time message monitoring. A computing platform may monitor a plurality of messages received by a messaging server associated with an operator. Subsequently, the computing platform may detect that a message of the plurality of messages is potentially malicious. In response to detecting that the message of the plurality of messages is potentially malicious, the computing platform may execute one or more protection actions. In executing the one or more protection actions, the computing platform may generate an alert message comprising information indicating that the message of the plurality of messages is potentially malicious. Then, the computing platform may send the alert message to the messaging server, which may cause the messaging server to deliver the alert message to a computing device associated with an intended recipient of the message.