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You will find below definitions of terms and phrases commonly used in emailing or computing. This is a living glossary, and suggestions are welcome for additions or corrections. Please send your comments to


Click on to have more details on the eMill feature relative to the defined term.



The part of an email or web page that is visible without scrolling. It is generally more desirable placement because of its visibility.

Acquisition cost

It represents the cost of reaching the objective of a campaign (generation of leads, new subscribers or members). It is calculated by dividing total campaign expense by the number of new leads, subscribers or members.

Active Messaging Script

Active Messaging Script (AMS) is a server-side scripting language developped by eMill engineers in order to make it easy to build powerful custom messaging applications. eMill uses AMS to combine HTML or TXT message content with external data source records supplied by any database it connects to. Since it shares a lot with existing popular scripting languages, beginners will experience a similar learning curve. Developers familiar with ASP and Visual Basic scripting will instantly feel at home.

Affirmative consent

According to The US Senate Commerce Committee Report for the CAN-SPAM Act, the 'affirmative consent' represents an active request by a reader or a subscriber to receive promotional information, newsletters, etc.  It does not include passive action such as not unchecking a pre-checked box or other default Web form.


Email message that notifies subscribers of an event (launching of a product, trade fair) or special offer.

Alternate Text (Aka Multipart Message)

Most mail clients today support both text and HTML emails. However, some recipents may configure their email client to block HTML contents preventing your message to be displayed. That is why eMill gives you the possibility to send a multipart email that contains an HTML part and an alternate text. The email client will display the format most suited to its environment, HTML for HTML capable clients, plain-text for text only clients.

Application Program Interface (API)

It represents how an application can interact with another to transmit data. For an emailing solution, this can be useful to communicate with a CRM or eCommerce solution to load database information and to feed your system with data from the e-mail.

Application Service Provider (ASP)

Company that provides a Web-based service. Clients don’t have to install software on their own computers; all tasks are performed on the ASP’s servers.


A file (text, zip, pdf, sound, video) that accompanies an email message but is not included in the message body. Beware that some email clients may automatically delete attachments because they are sometimes used by hackers to send viruses.


An automated process that verifies an email sender's identity (DomainKey, SenderID, SPF).


Possibilities to send email messages when new information are received from a contact: welcome message, unsubscription message, subscription confirmation message. It also represents series of messages and event-triggered emails (birthday, purchase anniversary).



Bayesian filter (Aka content-based filter)

Program that evaluates the probability that your message can be considered as a spam. Bayesian filters assign point values to items that appear frequently in spam, such as the words "money-back guarantee" or "free." A message that accumulated too many points is either rejected as probable spam or delivered to a junk-mail folder.


When a mail server refuses to deliver a message to the final recipient. This happens when a message is flagged as a Spam by filters or if the IP address or domain names are blacklisted.


1. List developed by anyone receiving email that includes domains or IP addresses of any emailers suspected of sending spam. Blacklists are then used to reject inbound email, either at the server level or before it reaches the recipient’s in-box.

2. List built by the sender of an e-mailing campaign. It includes all the contacts that will be ignored when renderding campaign messages.


A message that is not delivered properly is said to have bounced. Emails can bounce for many reasons: the email address is incorrect or has been closed; the recipient’s mailbox is full, the mail server is down, or the system detects spam or offensive content. See bounce message, hard bounce and soft bounce.

Bounce handling

Represents the process of dealing with bounce messages. Bounce handling is important for list maintenance, list integrity and delivery.

Bounce message

Message created by the recipient mail server that provides information on the current status of the message.  A bounced email is classified as either a "hard bounce" or a "soft bounce." Note that all bounce messages are not standard or accurate. According to recent studies, only 60% of SMTP Servers delivers standard bounce messages.

Bounce rate

Number of emails that have bounced divided by the total number of emails sent (usually express as a percentage). This can be an inexact rate because some servers do not report back to the sender clearly or accurately.


Process of simultaneously emailing the same message to multiple recipients.



Call to action

Represents a link or a text that tell the recipient what action to take.


U.S. law regulating commercial email (Full name: Controlling the Assault of Non-Solicited Pornography and Marketing Act of 2003)


Common Gateway Interface. Specification for transferring information between the Web and a Web server, such as processing email subscription or contact forms.

Challenge-response system

Anti-spam program that requires an action of a human being on the sender's end to respond to a message before their messages can be delivered to recipients. Senders who answer the message are added to an authorization list. Email marketers should always watch the sending address' mailbox in order to reply to each challenge by hand.


Number of unsubscribers divided by the total number of contacts in the mailing list (usually express as a percentage).


When a receiver takes an action and clicks on a link.

Clickthrough rate

Number of clicks on email links divided by the total number of emails sent (usually express as a percentage). It includes multiple clicks by a unique user.

Client-server database

This term represents a database where the data and an intelligent manager application for it reside on a "server" computer. "Client" applications on remote computers make specific demands for data as they require it usually using a Structured Query Language (SQL). Rather than sending the entire data file to the application to be dealt with, the server software sends only the data required by the application request. (e.g.: SQL Server, Oracle,...)

Commercial email

Any email message the primary purpose of which is is to sell or advertise a product or service or if its purpose is to persuade users to perform an act, such as to purchase a product or click to a Web site whose contents are designed to sell, advertise or promote.


Arrangement between 2 companies where the first one offer in its subscription or registration form the possibility to be added  to a specific third-party list.


Customer Relationship Management technology and systems



Dedicated Server

SMTP server used by only one sender. A dedicated server often costs more to use because the expense can't be spread among many users, but it performs better than a shared server. Email usually goes out faster, the server is more secure, and you eliminate the possibility that another sender could get the server blacklisted for spamming.


Removing identical records from your mailing lists.

Delivered email

Number of emails sent minus the number of bounce messages. An inexact number because not all receiving mail servers report accurately on which email didn't go through.


A shortened version of an email newsletter which replaces full-length articles with clickable links to the full article at a Web site, often with a brief summary of the contents.

Domain Name System

System that locates Internet domain names and translate them into IP addresses. The domain name is the name for an IP address or range of IP addresses. See reverse DNS.

Double opt-in Email (Aka Confirmed opt-in)

The double opt-in is a two-step process to allow a user to subscribe to your list. When someone submits his details on your website, he is not immediately added to a mailing list. Instead, an email is sent to his email address, asking to confirm that the name should indeed be added. If the recipient of the confirmation email does nothing, the submitted address is not added to the mailing list.

Dynamic content

Email content that changes from one recipient to the next according to a set of predetermined rules or variables. Dynamic content can reflect past purchases, current interests or where the recipient lives.



Email address

An email address is composed of a unique user name and a sender domain (

Email Appending

Practice of using offline data to match profiles with users and contact via e-mail.

Email Client

Program or application used to read email (Outlook Express, Thunderbird, Lotus Notes,...).

Email Domain

Portion of the email address to the right of the @ sign.

Email Format

Emails currently can only be delivered in plain-text or HTML format. Email Marketers needs to consider the target audience and the goal of the message to determine which is the more appropriate format for any specific campaign.

Email Frequency

Intervals at which email marketing campaigns are repeated: weekly, bi-weekly, monthly, bi-monthly, etc.

Email Display Name (Aka Friendly Name, From name)

Portion of the email address that is displayed in most email readers in place of, or in addition to, the email address. The full format of an email address is "DisplayName" <>.

Email Marketing Campaign

Coordination of email marketing messages delivered at intervals with an overall objective in mind.

Email Newsletter

Email message sent to subscribers on a regular schedule with relevant information on a topic. Often used to capture Web site visitor's email addresses, they can also be used to keep in touch with existing customers, or simply as a means of distributing new information product.

Email to SMS Gateway

SMSC which servers convert automatically the emails they received into SMS messages. Then, they deliver them to the final receiver.

Event Triggered Email

Email message sent automatically when an event occurs such as a date or anniversary.



False positive

Legitimate Email message mistakenly rejected or filtered as spam.

Field Merging

Practice of personalizing an email message (message body or subject line) with the information coming from your mailing list.

File based database

File-based database like Microsoft Access store their data in data files that are shared by multiple users. These data files are usually stored on network drives so that they are easily accessible to all users who need them. When you access data from a Microsoft Access table, for example, that data file is opened on your computer. Any data that you read is read by Microsoft Access running on your computer. Likewise, any data changes are made locally by the copy of Access that is running on your computer.


Program designed to protect private network from unauthorized users or messages. The firewall usually has rules or protocols that authorize or prohibit outside users or messages. In email, a firewall can be designed so that messages from some domains or users will not be delivered.


Text or image at the end of an email message that doesn’t change from one edition to the next (contact information, company’s postal address, recipient email address).



Geo Targeting

The ability to target users by geography such as city, state, country and zip code.

Goodbye message

Email message sent automatically to a list member who unsubscribes. It always includes an option to resubscribe in case the unsubscribe was requested accidentally.



Hard Bounce

Bounce message informing the sender that the email message cannot be delivered to the recipient due to a permanent reason.  Hard bounces are not vaild email addresses and should be removed from lists.


Data at the start of an email message which includes the sender's name and email address, the originating email server IP address, the recipient IP address, the route it's taken across the Internet and any other customize headers. Headers that are usually seen by the recipient are the "to" (identity of recipient), "from" (identity of sender) and "subject" (information in the subject line).

House list

Mailing list developed by an organization on its own.

HTML message

Email message which contains any type of formatting other than text. It also includes any graphic images, logos and colors.



Images - Remote or Embedded?

When creating an e-mail with images, you must decide whether you want to include remote or embedded images.

The choice between these 2 techniques depend on your equipment (bandwidth, web server), your target (B2B, B2C, behaviour, infrastructure) and the image (image size, is the message understandable without the image?, is the image critical or not?).

IP address

Unique number assigned to each device connected to the Internet. An IP address can be dynamic, meaning it changes each time an email message, or it can be static, meaning it never changes. When using the built-in SMTP server, static IP addresses are best, because dynamic IP addresses often trigger spam filters.

ISP (Internet Service Provider)

Business or organization that gives individuals or companies access to the Internet. ISPs often rent Internet connections and offers complementary online services.



List management

Global term that represents how a mailing list is set up, administered and maintained: processing subscribes and unsubscribes, bounce management, list hygiene, etc.



Mailing List

A group of email addresses (with or without additional information) to which you send your emailing campaign.


Code used to make clickable an email address in either a text or HTML email ( When the link is clicked, it usually opens the user's email client and inserts the email address in the To: link of a blank message.


Mail Transfer Agent. Computer that forwards email from senders to recipients and stores incoming email.

MSP (Aka Webmail)

Mail service provider such as Hotmail, Yahoo!, Gmail,...

MUA (Aka Email Client)

Mail User Agent. Program or application used to read email (Outlook Express, Thunderbird, Lotus Notes,...).

Multi-part Message (Aka Alternate Text)

See Alternate Text.




ODBC is an interface allowing eMill to connect to a database and retrieve the data. Indeed, ODBC allows programs to use SQL queries that will access databases without having to know the proprietary interfaces to the databases. It handles the SQL query and converts it into a request the individual database system understands. Most current databases support ODBC which means that computer programslike eMill that rely on ODBC can connect to several different brands of databases using the same basic code.

Open rate

Number of message recipients who opened your email divided by the total number of emails sent (usually expressed in percentage). It is considered as one of the key rate to evaluate an email campaign's success.


Action a person takes when he or she actively agrees to have their own email address placed on a specific mailing list. see Double Opt In


Action a person takes when he or she chooses to have its email address deleted from a specific mailing list.



Pass-along (Aka Viral)

Email recipient who received your message via forwarding from one of your subscriber. If you encourage a recipient to forward your message, you must consider the fact that it can affect the formatting of the email.


Targeting method in which an email message appears to have been created only for a single recipient. Personalization can include a number of things: mail merge (body, subject line), dynamic content, event troggered emails,... All email marketing analysis demonstrate that the more your email message is personalized the more the recipient will be encouraged to read the content.

Plain text

Text in an email message that includes no formatting code.


Post Office Protocol version 3 (POP3) is an Internet standard protocol used to retrieve email from a remote server to a local client over a TCP/IP connection. Nearly all individual Internet service provider email accounts are accessed via POP3.


Person to contact at a Web site, ISP or other site to request information, get help with delivery or register complaints.



Relationship email

Email message that refers to a commercial action (a purchase, complaint or customer request).


Email address that receives messages sent from users who click “reply” in their email clients. By default the Reply-To address is the From Address but can be customized in the message headers.

Reverse DNS

The process in which an IP address is matched correctly to a domain name, instead of a domain name being matched to an IP address. Reverse DNS is a method commonly used for catching spammers who use invalid IP addresses. If a spam filter can't match the IP address to the domain name, it can reject the email. That is the reason why, it is recommended to send emails using a static IP address.




Process of slicing a list into specific pieces determined by various attributes.

Sent emails

Number of email messages sent for one emailing campaign.

Shared server

SMTP server used by more than one company or sender. They are usually less expensive to use because the cost can be spread over more users. However, note that senders sharing a server risk having emails blocked by some recipient mail server if one of the user does something to get the server's IP address blacklisted.


Short text or image found in the closing of an email. Signatures can include advertising information, such as a company name, product, brand message or marketing call to action.

S/MIME Protocol

S/MIME (Secure / Multipurpose Internet Mail Extensions) is a standard for encryption and digital signature of emails in MIME format. This protocol is based on the use of certificates delivered by specialized companies like VeriSign, Thawte or Comodo Group. In Windows, certificates are listed in stores. In order to display the stores and certificates list installed on your computer, you need to open a new MMC and add Certificates, a snap-in software component. Each certificate includes 2 keys: a private and a public one. They will be used differently whether the sender wants to encrypt or sign the message.

SMPP Server

The short Message Peer-to-peer Protocol is a standard protocol for exchanging SMS messages between different entities. It is often used by organizations to broascast bulk SMS campaigns.

SMS (Short Message Service)

Service offered by most mobile communication networks which allows their users to send and receive short alphanumeric messages (around 160 characters).

SMSC (Short Message Service Center)

The Short Message Service Center stores and delivers SMS messages to the receiver when he is available. It can make the connection between two mobile phones or between an IP network (such as Internet) and a mobile phone.

SMTP Server

The Simple Mail Transfer Protocol (SMTP) is an internet standard protocol for sending electronic mail messages between computers. It establishes the connection between the sender and the receiver. For sending out your emailing projects, you can either use the built-in SMTP server, your ISP SMTP Server or any other SMTP server.

Soft Bounce

Bounce message informing the sender that the email message cannot be delivered to the recipient due to a temporary reason. Soft bounces can be valid or invalid email addresses. If you receive soft bounces regarding the same recipient for multiple email campaigns, the contact should be removed from lists.

Spam (Aka UCE)

Term normally given to commercial email sent without the recipient's permission. Those accused of sending UCE can run into trouble, ranging from impolite responses through loss of Internet access accounts to destruction of reputations and infrastructure.


Blacklist and IP-address database used by many IPSs to filter incoming messages and determine whether the address has been blacklisted due to spam complaints. See Blacklists.

Spam Trap

Email addresses that have been specifically created to detect individuals who have illegally scraped or collected email addresses. The belief is that any email sent to a spam trap address is indeed Spam, as the email address is not usually used as a real email address.

SPC Protocol

Communication protocol to easily connect an eMill server to remote eMill Windows clients. The connection is established through the Internet using the TCP Port 2156 (by default). Find out more in the Multi-user Architecture section.

SQL (Structured Query Language)

Standard interactive and programming language for getting information from and updating a database. Queries take the form of a command language that lets you select, insert, update, find out the location of data, and so forth.<:p>

Subject Line

Title of an email message. This is the first element of the message recipients will see when they access their email. Therefore, it has to grab attention to incite recipients to open it (personalized subject, incentive sentence,...).


Process of being added to a mailing list, either through an email, by filling out an online subscription form, or offline by filling out a form or requesting to be added verbally.


Person who has specifically requested to be added to a mailing list.




Term that represents the fact to send the right message to the right recipient at the right time.

Thank-you page

Web page that appears after user has submitted an order or a form online.


Practice of regulating how many email message is sent at a time. Recipient mail servers may block messages if they receive too many messages from one sending address at a time.


Collecting statistics from which you can measure the effectiveness of an email campaign. See open rate and clichthrough rate.



UCE (Aka Spam)

Unsolicited Commercial Email. Term normally given to commercial email sent without the recipient's permission. Those accused of sending UCE can run into trouble, ranging from impolite responses through loss of Internet access accounts to destruction of reputations and infrastructure.


To remove oneself from a mailing list, either via an emailed command to the list server or by filling in a Web form.

URL (Uniform Resource Locator)

Web address for a page. It is always composed of "http://" (or https:// for a secure page), followed by "www.", and the domain name.



Webmail (also Web mail, MSP)

Term that regroups all Web-based email clients: Gmail, Yahoo!, Hotmail...

Welcome message

Email message sent automatically to someone who has just subscribed to a mailing list.


List of email addresses built by an ISP or other email service provider. It allows email messages to be delivered without being filtered by anti-spam programs.


A HTML editor is an application software for creating webpages. Although the HTML code can be written with any text editor, HTML editing software often offers convenience and functionality. WYSIWYG editors are specific HTML editors which provide an editing interface which resembles how the page will be displayed in a web browser or mail client. It also have a mode to edit HTML directly like a text HTML editor. Because using a WYSIWYG editor does not require any HTML knowledge it is easier for an average computer user.