Scam Sensor is an Outlook add-in that constantly monitors every e-mail the user reads. When Scam Sensor detects phishing techniques being used in the e-mail, it warns the user about the danger of visiting sites mentioned in this e-mail or replying to the message. The user does not have to click on any buttons to check a suspicious e-mail. Scam Sensor checks every e-mail the user reads automatically. The user cannot even turn Scam Sensor off and avoid the e-mail check. Scam Sensor does not use any online databases of fraud e-mails or forged hyperlinks. Instead, the program uses a set of special algorithms which use information received from an e-mail message to determine whether the message tries to cheat the reader. No algorithmic training is needed.