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Glossary
A record
A records map a host name to an IP address.
ADDR
This type of black list uses a message's FROM address to determine whether the message is spam.
Alias
An alias is another name assigned to a host name that can be used in place of the host name (plus domain name). Aliases are often used to shorten long host names for convenience.
Authenticated User
Users who have SMTP Authorization enabled on their e-mail client. By default IMail Server forces users to authenticate, unless you enter their IP address in the Access Control dialog box. This means that every time they connect to the IMail server, they must enter their user ID and password.
Baud rate
The rate (measured in bits per second) at which the serial port for the MONITOR server will communicate with the modem.
Backup Domain Controller (BDC)
Maintains a read-only backup of the Primary Domain Controller's (PDC) master directory. A backup domain controller cannot be changed, but it can be synchronized with or upgraded to a primary domain controllers.
Cache
Each time the Domain Name Server processes a lookup request for a host not in its domain, it must query another name server for the information. When a reply is received, the DNS saves the information in a cache. The next time it receives a query for the same information, it does not have to query another name server. Since address data in the Domain Name System changes often, the system administrator assigns a Time to Live (TTL), after which the cache is cleared.
Client
A client is a program running on a networked computer that requests services from a server program, which is usually running on another networked computer. The client communicates with the server using a protocol. For example, an FTP client communicates with an FTP server using the FTP protocol.
CNAME
A CNAME is a domain alias entry in the DNS record that points a hostname to another hostname.
Connection Filtering
Examines aspects of a connecting SMTP server to determine whether the IP address is listed in any black lists. Connection filtering also checks messages using validation tests to see whether they have valid connections.
Content Filtering
Content filtering consists of phrase and statistical filtering, and examines the body of an e-mail to determine whether it is spam.
DLL
Dynamic Link Library is a library of executable functions that can be used by an application. A DLL provides one or more functions and a program accesses the functions by creating a link to the DLL.
DNS Black List
This type of black list checks the IP address of the connecting SMTP server against spam databases to determine if the message is spam.
Domain
A term that refers to the subdivisions of the Internet network. Domain can mean the major subdivision of which your network is a part (.com, edu, .gov, .net, .us, .uk) or it can refer to your part of the network ( ipswitch.com). See also Domain Name System.
Domain Name System
A distributed database system that translates host names (for example, tortoise.ipswitch.com) to IP addresses (for example, 156.21.50.10). All hosts on the Internet are named using the conventions specified by the Domain Name System. Host Names are used because they are easier to remember than numerical addresses (IP addresses). An example host and domain name is tortoise.ipswitch.com, where tortoise is the host name, and ipswitch.com is the domain name. The domain represents the network where the host is located.
Domain name server
A host that keeps a table of host names and IP addresses, and provides the lookup service for client programs. A domain name server is used by client programs to look up the IP address of a host. A domain name server provides host name to IP address mapping for the local network and provides access to the Domain Name System to look up hosts in other domains.
A primary name server contains all the information for the domain in its database files. If you add a second name server for backup or to off-load the primary server, you can set it up as a secondary server. A secondary name server obtains its domain information by copying the database files from the name server that is primary for that domain. The advantage of using secondary servers is that you can maintain the domain information on one name server (the primary).
Exclude List
A list of words that are not to be included in determining whether a message is spam. The words in the exclude list have an equal chance of being spam or non-spam. The exclude list should include common words like html tags, and proper names, and is stored in the exclude-list.txt file located in the host's directory.
False Positive
A false positive is when an e-mail message is identified as spam when it is legitimate mail.
Finger
Finger protocol is a common Internet language that allows remote users to see information about users registered on a system. This includes the full name of the specified user, his or her complete e-mail address and a "plan" file provide by the user that contains additional information the user wishes to provide in response to Finger requests.
FQDN (Fully Qualified Domain Name)
A Fully Qualified Domain Name consists of a host and a domain name. For example, www.ipswitch.com is a fully qualified domain name. Where www is the host, ipswitch is the second-level domain, and .com is the top level domain.
FTP
FTP stands for File Transfer Protocol. This is one of the standard protocols defined for use on a TCP/IP network and used to transfer files between systems.
Gate host
Gate Host is the name of another host to send mail to when the mail cannot be delivered directly to the destination host.
HELO/EHLO Black List
This type of black list checks the domain supplied in the HELO or EHLO command to determine whether to accept the message.
HTML Filtering
HTML filtering consists of feature filtering and the URL Domain Black List. It examines the body of an HTML e-mail and searches for HTML tags and domain names in URL links., to determine if the e-mail is spam.
IMAP4
Internet Message Access Protocol version 4 (IMAP4) is a method of accessing electronic mail messages that are kept on a (possibly shared) mail server. It permits a client e-mail application to access remote message stores as if they were local.
in-addr.arpa domain
A special domain on the Internet that maps IP addresses to domain names. This domain is used to do reverse lookups, where the IP address is known and the application is querying for the host name.
IP (Internet Protocol)
The protocol that determines how packets (bundles of data) traverse the Internet network to find their destination. See also TCP.
IP address
All hosts on the Internet are identified by a unique numeric code, called the IP address. 156.21.50.1 is an IP address. The Domain Name System is used to map the IP address to a name.
LDAP
Lightweight Directory Access Protocol is a way of accessing directory information stored on a server. It permits an LDAP-enabled client to search for and view user information stored in an LDAP directory.
List Administrator
The User ID on the current mail host that can administer the list using Web Messaging. This person can modify list properties, add/delete users, and edit all related files. The list administrator and the list owner are usually the same person.
List Owner
The person who receives all messages (such as Subscribe and Unsubscribe requests, and error messages) to the list. It is also the account to which all messages are sent to the list, from anyone who requests information about the list, and in response to invalid attempts to post to the list. The list owner and list administrator are usually the same person. On a moderated list, the list owner is also the list moderator.
List server
A list server provides an automated way to manage mail discussion groups. All messages for a mail discussion group received by a list server are sent to all the members of that mail discussion group.The list server manages the adding and removal of users from the subscriber list and the distribution of messages to all subscribed users.
MX record
The MX record identifies the host name of the computer running the mail server (in this case, the IMail Server computer).
Name server
Namespace
ODBC
Open DataBase Connectivity is a standard database access method that makes it possible to access data from any application, regardless of which database management system (DBMS) is handling the data. ODBC inserts a layer, called a database driver, between an application and the DBMS. This layer translates the application's data queries into commands that the DBMS understands.
Phrase Filtering
Phrase Filtering searches for configurable spam phrases within the body of mail messages to determine if a message is spam. The phrases are stored in the phrase-list.txt file, located in the host's directory.
POP3
Post Office Protocol version 3 (POP3) is the most common protocol for communicating with a mail server (otherwise known as a post office) to retrieve messages for a user. Since POP3 servers are always available to receive incoming mail, individual users do not have to have their PCs turned on at all times. POP3 servers hold mail for users until they connect to download their messages.
Postmaster Alias
Each host in IMail Server must have an alias of postmaster in order to comply with the SMTP RFCs. This allows messages to be sent to the server by other hosts, and also allow certain system messages (such as error messages) to be automatically generated. If the primary host uses the IMail database or an external database, the installation procedure creates a root user and a postmaster alias and points the alias to the user named root. The user ID of root is automatically registered, but the account is disabled by default.
Primary Domain Controller (PDC)
A server in a Windows NT network that maintains a directory of user accounts and security information, and authenticates usernames and passwords when users login. It allows users to have read and write access to all resources on the entire network, by only logging in to one domain.
Processing rules
Delivery rules direct incoming mail based on the contents of To, From, Sender, Subject, the message Header, or the message Body. Delivery rules can be applied for a domain, individual user or list-server mailing list.
Protocol
A set of rules that define how computers will exchange information.
PTR record
The PTR record maps an IP address to the host name and is used for reverse lookups.
Queue
The location where e-mail messages are stored while waiting to be delivered. IMail Server pulls the messages out of the queue one at a time and delivers them in the order that they were placed in the queue.
Relay
A message that originates on a computer other than the IMail Server host and is destined for another host, must pass through IMail Server. IMail server (or any SMTP server) then accepts the mail and redelivers it to that host.
Request for Comments (RFC)
A set of documents that define the Internet standards. RFCs are also used to propose new standards, or extensions to existing standards.
Reverse lookups
When the client program requests the host name of a given IP address, the DNS server does a reverse lookup. This is the reverse of the normal DNS lookup procedure, where the IP address for a given host name is sought. Reverse lookups use a special domain, the in-addr.arpa domain, which maps IP addresses to domain names.
RHS Black List (Right Hand Side Black List)
This type of black list checks the information following the @ symbol supplied in the MAIL FROM command to determine whether to accept the message.
Root User
Each host in IMail Server must have user ID of root to comply with the SMTP RFCs. This allows messages to be sent to the server by other hosts, and allows certain system messages (such as error messages) to be automatically generated.If the primary host uses the IMail database or an external database, the installation procedure creates a user named root and an alias named postmaster and points the alias to the user named root. The root user ID is automatically registered, but the account is disabled by default.
Server
A server is a program running on a networked computer that processes requests for services from a client program, which is usually running on another networked computer. The client and server communicate using a protocol. For example, an FTP client communicates with an FTP server using the FTP protocol.
Service
"Service" is a formal Windows NT/2000 term for an executable object installed in a registry database maintained by NT/2000's Service Control Manager. A service can be automatically started when the system is booted and continues to run until the system is shut down. It will continue to run even when no one is logged on the system.
SSL
Secure Sockets Layer (SSL) is used for communications between a browser and server. SSL encrypts mail communications so they can be read only by the intended recipients. SSL uses "certificates" to authenticate the client and server, and uses a public/private key "pair" to encrypt and decrypt communications. All of the major browsers are SSL enabled.
SMTP
Simple Mail Transfer Protocol (SMTP) is designed to efficiently and reliably transfer mail across TCP/IP networks, including the Internet. SMTP defines the interaction between mail systems to facilitate the transfer of electronic mail even when the mail systems are on different types of computers or running different operating systems. SMTP is required to send or receive mail over the Internet. IMail Server is an SMTP server.
Spam
Spam is any e-mail that is not wanted or requested by the recipient. Unsolicited bulk e-mail is an example of spam.
Spamming
When a bulk mailer sends unsolicited mail to other people, it is known as "spamming." Spam mailers may try to use your system to relay messages to other Internet mail users, tying up your valuable system resources. IMail Server provides anti-spamming features.
Statistical Filtering
Statistical filtering compares each word in the body of an e-mail with statistical word values, collected from previous spam and non-spam e-mail messages, to determine whether the message is spam.
TCP
Transmission Control Protocol; the protocol that controls how data is assembled and disassembled in packets. See also IP.
TTL
The Time to Live (TTL) specifies an amount of time (usually in seconds) for which a secondary name server can use the DNS database files that it copied from the primary server before it needs to refresh the data.
UDP
User Datagram Protocol; a transmission protocol for uses that do not require the control and error checking of TCP.
Filters out domain names and IP addresses that are often contained in url links in HTML messages. These are domain names that are known to send spam. IMail Server does this by examining the HREF and IMG SRC tags in the HTML code.
Verification tests verify the following information about a connecting SMTP server: the "Mail FROM" address, HELO/EHLO domain information, and perform a reverse DNS lookup.
White List
The white list contains e-mail addresses and domains from which mail is always accepted. Messages that originate from one of these addresses are processed immediately without under going content filtering or phrase filtering.
Whois
The Whois protocol is a common Internet language that allows remote users to search for mail addresses of users.
Winsock
Winsock is a specification that developers of TCP/IP network software for Microsoft Windows use as a guideline for the standard application programming interface to their network software.
Word Values
When statistical filtering is enabled, each word within an e-mail is assigned two word values: the number of times it has occurred in spam, and the number of times it has occurred in non-spam. These values are stored in the antispam-table.txt file.
 Ipswitch, Inc. http://www.ipswitch.com |
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