If the password is not found in the attachment or email and there are image files attached to the email, the Email Security - Server appliance can scan the images for passwords using OCR. You can configure image password extraction using the CLI only.
Image file types that are analyzed for passwords are JPEG, PNG, BMP, and TIFF.
Note
Image password extraction does not check the list of password, keyword, and ignored word candidates set in the Attachment decryption page in the Web UI.
File types added for scanning using the Malware File Associations settings are not considered in the algorithm for password analysis and extraction.
Image password extraction is independent of signature image analysis. For information on that feature, see Image and text files on .
Prerequisites
Image password extraction depends on the following:
The EMPS_ATTACHMENT_SCAN license is active. See Analysis scanning options on .
Image password extraction is enabled. See Enabling or disabling image password extraction using the CLI on .