Cisco Cisco Email Security Appliance C370 User Guide

Denial of Service attack, can also be in the form of DDos (Distributed Denial of 
Service Attack). An attack on a network or computer, the primary aim of which 
is to disrupt access to a given service. 

Delivery Status Notification, a bounced message.

A single, comprehensive dashboard to manage all email security services and 
applications on IronPort appliances. Email Security Manager allows you to 
manage Outbreak Filters, Anti-Spam, Anti-Virus, and email content policies — 
on a per-recipient or per-sender basis, through distinct inbound and outbound 
policies. See also Content Filters.

The recipient of an email message, as defined in the RCPT TO: SMTP command. 
Also sometimes referred to as the “Recipient To” or “Envelope To” address. 

The sender of an email message, as defined in the MAIL FROM: SMTP 
command. Also sometimes referred to as the “Mail From” or “Envelope From” 
address. 

A spam message or a message containing a virus or a DLP violation that was not 
detected as such. 

A message falsely categorized as spam or as containing a virus or DLP violation.

A domain name including all higher level domain names up to the top-level 
domain name; for example: 

mail3.example.com 

is a fully qualified domain 

name for the host at 192.168.42.42; 

example.com

 is the fully qualified domain 

name for the example.com domain. The fully qualified domain name must be 
unique within the Internet. 

A message that is permanently undeliverable. This can happen during the SMTP 
conversation or afterward.

Host Access Table. The HAT maintains a set of rules that control incoming 
connections from remote hosts for a listener. Every listener has its own HAT. 
HATs are defined for public and private listeners, and contain mail flow policies 
and sender groups.