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Implementing Cisco Networking Solutions by Harpreet Singh

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Email services

Email is the most commonly used attack medium by attackers. This is because emails cannot be detected by commonly used next generation firewalls as malicious, as they appear on the network as TCP/IP traffic that is allowed as per the organization's security policy.

Devices such as Email Security Appliance (ESA) from Cisco are special purpose devices that are tuned to detect any malicious traffic within emails. These devices act like the SMTP relay agents for the mail servers of the organization, and all traffic coming in from the internet and going out to the internet from the mail servers passes through the ESA devices. The ESA device does a deep lookup inside the application headers, including the email contents and the attachments, ...

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