Stands for 'address
record'. The A-record determines which IP address belongs to a domain name.
This record 'translates' the domain name to an IP address.
A directory service created by Microsoft for Windows domain
networks. Active Directory serves as a central location for network
administration and security. It is responsible for authenticating and
authorizing all users and computers within a network of Windows domain type,
assigning and enforcing security policies for all computers in a network and
installing or updating software on network computers.
For example, when a user logs into a computer that is part of a
Windows domain, Active Directory verifies that user's password and specifies
whether he or she is a system administrator or normal user. Active Directory is
LDAP compliant. Others active directories include Lotus Domino, SunOne/iPlanet
Directory Server and Novell eDirectory.
An open source content filter for email, implementing mail
message transfer, decoding, some processing and checking, and interfacing with
external content filters to provide protection against spam, viruses and other
malware.
A statistical technique of email filtering. It makes use of
a naive Bayes classifier to identify spam email.
Bayesian classifiers work by correlating the use of tokens
(typically words, or sometimes other things), with spam and non-spam emails and
then using Bayesian inference to calculate a probability that an email is or is
not spam.
Certain words have probabilities of occurring in spam email and
in legitimate email. For instance, most email users will frequently encounter
the word "Viagra" in spam email, but will seldom see it in other
email.
Classless Inter-Domain Routing (CIDR) is an IP addressing system that replaces an older system based on classes. One IP address can be used to designate several unique IP addresses using CIDR.
A CIDR IP address looks like a normal IP address but it ends with a forward slash followed by a number, call the IP network prefix - e.g. 10.10.10.10/24. CIDR makes more IP addresses available within an organisation.
An open-source antivirus software toolkit able to detect many
types of malicious software, including viruses. It is a powerful, fast, and
most importantly accurate virus detection engine that uses a scalable,
multi-threaded daemon to scan for viruses and viruses.
The delivery of computing as a service rather than a product,
whereby shared resources, software, and information are provided to computers
and other devices as a metered service over a network (typically the
Internet).
Cloud computing is a marketing term for technologies that
provide computation, software, data access, and storage services that do not
require end-user knowledge of the physical location and configuration of the
system that delivers the services.
A computer cluster consists of a set of loosely connected
computers that work together so that in many respects they can be viewed as a
single system. Each component of a computer cluster is referred to as a
'Node'.
An email spamming technique whereby a spammer sends out
thousands of emails with randomly generated addresses using combinations of
letters in the hopes of reaching a percentage of actual email addresses.
Domain Keys Identified Mail (DKIM) is an email authentication
method designed to detect email spoofing.
Domain-based Message Authentication, Reporting and
Conformance (DMARC) is an email-validation system designed to detect and
prevent email spoofing.
Domain Name System (DNS) is a hierarchical distributed naming
system for computers, services, or any resource connected to the Internet or a
private network.
An often-used analogy to explain the Domain Name System is that
it serves as a phone book for the Internet by translating human-friendly
computer hostnames (e.g. www.example.com) into IP addresses (e.g.
192.1.1.).
A false negative means a spam email came through as clean (less
than the default score of 5).
A false positive means a clean email was marked as spam (more
than the default score of 5).
The complete domain name for a specific computer (host) on the
Internet. The FQDN, which includes the hostname and domain name, is converted
into a physical IP address.
Greylisting temporarily rejects all email and requires the
sending server to send it again after 5 minutes. This delay is beneficial as:
· Spammers will generally not retry to send an email,
while legitimate servers do.
· The delay gives time for an IP address to be listed on
RBLs if it is spam.
While greylisting is highly effective at blocking spam it comes
at the cost of mail being delayed by 5 to 10 minutes, depending on the sending
server.
Short for malicious software, malware is software designed to
disrupt computer operation, gather sensitive information, or gain unauthorized
access to computer systems.
It is a general term used to describe any kind of software or
code specifically designed to exploit a computer, or the data it contains,
without consent. Malware includes computer viruses, worms, Trojan horses,
spyware, dishonest adware, most rootkits, and other malicious programs.
An architecture in which a single instance of a software
application serves multiple customers and each customer is called a tenant.
Tenants may be given the ability to customise some parts of the application,
such as the colour of the user interface or business rules, but they cannot
customise the application's code.
A DNS server record that contains information about which mail
server the domain uses to receive mail. An MX record can point to a mail server
or a proxy server when there is a hosted mail filtering process in place.
An automated message from a mail system, informing the sender of
an email that was not delivered (or some other delivery problem occurred). The
email is said to have "bounced".
Also known as a bounce message, non-delivery receipt, delivery
status notification (DSN) or non-delivery notification (NDN).
A protocol used to synchronise computer clock times in a network
of computers. NTP uses Coordinated Universal Time (UTC) to synchronise computer
clock times to a millisecond, and sometimes to a fraction of a millisecond.
Phishing is a fraudulent act whereby a target or targets are
contacted by someone posing as a legitimate institution to lure them into
providing sensitive data such as personally identifiable information, banking
and credit card details, and passwords. Phishing websites lure email recipients
and Web users into believing that a spoofed website is legitimate and genuine.
The information is then used to access important accounts and
can result in identity theft and financial loss. Phishing is typically carried
out by e-mail spoofing or and it often directs users to enter details at a fake
website whose look and feel are almost identical to the legitimate one.
Post Office Protocol is an application-layer Internet standard
protocol used by local e-mail clients to retrieve e-mail from a remote server
over a TCP/IP connection.
A quarantine report shows a list of emails which have not been
sent to a user because they potentially contain spam or viruses. The user can
decide to deliver, whitelist (see Whitelisting) or delete the emails in the
quarantine report.
Also known as Blacklist, Domain Name System-based Blacklist
(DNSBL) or DNS Blacklist. The term "blackhole list" is also
interchanged with the terms "blacklist" and "blocklist".
These lists are maintained to stop email spamming by allowing
administrators to block messages from specific locations that have a history of
sending spam. If the maintainer of a DNS Blacklist has in the past
received spam of any kind from a specific domain name, that server would be
"blacklisted" and all messages sent from it would be either flagged
or rejected from all sites that use that specific list.
Secure Sockets Layer (SSL) is a standard protocol used for the
secure transmission of data between a client and server over a network.
SSL uses Transport Control Protocol (TCP) for communication.
When using SSL for secure Internet transactions, a Web server needs an SSL
certificate to establish a secure SSL connection. SSL encrypts network
connection segments above the transport layer, which is a network connection
component above the program layer.
SSL is the predecessor of Transport Layer Security (TLS).
SPF allows the owner of a domain to use special DNS records to
specify which machines are authorised to transmit e-mail for that domain. When
receiving a message from a domain, the receiver can check the DNS records to
ensure the mail is coming from locations that the domain has authorised.
When enabled, messages that fail the SPF test will be rejected.
This option is disabled by default as it can result in mail being rejected from
domains with incorrectly configured SPF records.
Smart Host
A mail server configuration which allows Z Services Email
Cluster to send mail via an intermediate server instead of sending mail
directly to recipient’s servers.
Simple Mail Transfer Protocol is an Internet standard protocol
for sending email across Internet Protocol (IP) networks. User-level client
mail applications typically only use SMTP for sending messages to a mail server
for relaying.
The use of email systems to send unsolicited bulk messages
indiscriminately. Email spam, also known as junk email or unsolicited bulk
email (UBE), is a subset of electronic spam involving nearly identical messages
sent to numerous recipients by email.
Spam averages 78% of all email sent and is often higher.
The creation of email messages with a forged sender address to
mislead the recipient about the origin of the message.
A type of malware that collects information about users without
their knowledge.
Spyware programs can collect various types of personal
information, such as Internet surfing habits and sites that have been visited
but can also interfere with user control of the computer in other ways, such as
installing additional software and redirecting Web browser activity.
The set of communications protocols used for the Internet and
other similar networks.
It is known as TCP/IP from its most important protocols:
Transmission Control Protocol (TCP) and Internet Protocol (IP), which were the
first networking protocols defined in this standard.
Transport layer security (TLS) is a protocol that provides
communication security between client/server applications that communicate with
each other over the Internet. TLS is used to secure web browsers, web
servers, VPNs, database servers and more. TLS evolved from Netscape's
Secure Sockets Layer (SSL) protocol and has largely superseded it, although the
terms SSL or SSL/TLS are still sometimes used.
TLS protocol consists of two different layers of sub-protocols:
· TLS Handshake Protocol: Enables the client and server
to authenticate each other and select a encryption algorithm before sending
data.
· TLS Record Protocol: It works on top of the standard
TCP protocol to ensure that the created connection is secure and reliable. It
also provides data encapsulation and data encryption services.
A computer program which appears harmless, but is malicious.
Typically, the malware is hidden in an innocent-looking attachment or download.
When the user clicks on the attachment or downloads the program, the malware
that is hidden inside is transferred to their device.
URIBL.com is a service that distributes information about domain
names as they are related to email, primarily Unsolicited Bulk/Commercial Email
(UBE/UCE).
This data is used to complement existing Anti-Spam software.
URIBL is enabled by default in the open source SpamAssassin software and
several other commercial offerings.
A malicious computer program that can replicate itself and
spread from one computer to another.