Secured electronic communication system

Systems and methods are described for detecting that a potential renter of a property is being fraudulently impersonated by a third party during electronic communications with an owner or lessor of the property. Data representing an exchange of electronic messages between an inquirer and a responder are obtained, and may be anonymized to prevent the parties from learning one another's identity prior to completing the transaction. The data may be compared to historical inquiries sent by the inquirer, historical inquiries received by the recipient, or other content of the electronic messages to determine a degree of risk that the inquirer's account has been compromised or is otherwise being fraudulently represented. The degree of risk may be communicated to the recipient, and may be acted upon by, e.g., blocking messages from an inquirer whose degree of risk exceeds a threshold.