1. A computer implemented method for detecting malicious network content by a network content processing system, comprising: receiving an electronic email message; analyzing the electronic email message to detect a uniform resource locator (URL) address within message content of the electronic email message; determining whether the detected URL address within the message content is suspicious; in response to a determination that the detected URL address is suspicious, executing, with a computer processing system, the suspicious URL address detected within the message content of the electronic email message, wherein executing the suspicious URL address comprises executing, within a virtual environment, web content received in response to a request for the web content; and identifying the suspicious URL address detected within the electronic email message content as malicious based on results of the executing of the suspicious URL address detected within the electronic email message content in the virtual environment.