Glossary for users
Backscatter
A return message for an undeliverable email (bounce message) that is not sent to the actual sender of the email.
Botnet
A botnet is a loosely grouped array of computers that are controlled by an unauthorised person. Unknown to the owners, a software that accepts jobs from an unauthorised person is installed on these computers. These jobs can include infecting other computers to extend the botnet, sending spam, or other kinds of misuse.
Email header/Email body
The email header contains technical information on the process of sending an email. Most email programs and webmail interfaces hide the email header.
In contrast to this, the email body (the text itself) is typically displaced. The body can be pure text or comprise multiple elements such as text and attachments.
False Positive/False Negative
Spam filters apply various criteria to access an email. It is technically impossible to evaluate with one hundred percent accuracy. If a desirable email is incorrectly identified as spam, this is referred to as a false positive. A false negative occurs when a spam email is not identified as such.
IP address (dynamic/static)
Short for Internet Protocol Address. An IP address comprises a numeric code of four numbers between 0 and 255 (e.g. 217.72.195.42). More recent IP addresses (IPv6
) are far longer and include numbers and the letters a-f separated by colons (e.g. 2001:8a2e:0370:0db8:85a3:7344:08d3:1319). This is the numeric address of a specific computer on the internet. Based on the IP address a computer on a network can be uniquely identified.
To remove the need for users to remember numbers, the Domain Name System converts IP addresses into alphanumeric designators. Thus, the IP address 74.208.4.12 resolves to 1and1.com.
Because IP addresses are a limited resource, private connections are typically assigned a dynamic IP address. If a connection with a dynamic address is interrupted, the next free address is assigned when the user dials up the network again.
In contrast to this, a static IP address is mainly used for computers that offer services on the internet, and need to be available on the same IP address (e.g. 1and1.com).
Bounce message
A bounce message is an error message sent from an email server to the original sender if the email is not deliverable. This is also referred to as a Delivery Status Notification (DSN).
Phishing
Phishing emails attempt to capture the personal data of user. A user is typically asked to enter their credentials for a mailbox, credit card information, credentials and transaction numbers for an online bank account etc. To allow this to happen, the phisher
spoofs emails to give the victim the impression they are talking to a trustworthy company.
Proxy server
A proxy server provides an interface on a computer network. A proxy server helps all the computers attached to the network to communicate with the outside world. Mobile network operators often use proxy servers to control internet communications from mobile devices.
RBL (Realtime Blackhole List)
An RBL list collects IP addresses. The list can be used to decide before establishing a connection if specific email senders are allowed to deliver to the receiving system, and to evaluate the spam probability with which emails are tagged. There are various types of lists of this kind. Some include IP addresses from which the owner is not prepared to receive and to which they are not prepared to send emails. Other lists include IP addresses which are known to be responsible for sending spam mail.
Scam
Scam is a special kind of spam mail where the recipients are fooled into believing that they can win a large sum of money or transact a lucrative business deal. The recipient of the email is then asked to pay a sum of money up front, but will not receive whatever was promised if they do so.
