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Important terms in email marketing

Important terms in email marketing

7 Bit Encoding

A reference to the ASCII character set, which is a set of 128 English alphabet characters and is used to store letters in binary. The set includes all the English lowercase letters, uppercase letters, and numbers from 0 to 9.The reason for the characters to be encoded to 7-bits, is because early computers handled data in bytes, or 8 bits. The extra bit was originally reserved for error checking.In this encoding we get 7 digit representations in 0s and 1s for each of the English letters we are trying to transmit.

A Record

Is what links your dedicated IP address to your chosen subdomain. Creating this record will, for example, point traffic for back to your dedicated IP, and vice versa.You can create multiple A records for a domain with as many IP addresses as you wish, however you can only whitelabel one IP to one domain at a time.

Abandoned cart email

It’s a triggered email that is sent to said customer, enticing them to come back and complete their purchase.When done in a non-creepy way, it can be a boon to your bottom-line. When done in a creepy way, it’s an express train to a restraining order.

Acquisition cost

In email marketing, the cost to generate one lead, newsletter subscriber or customer in an individual email campaign; typically, the total campaign expense divided by the number of leads, subscribers or customers it produced.

Ad swap

An exchange between two publishers in which each agrees to run the other's comparably valued ad at no charge. Value is determined by rate card, placement, size of list, quality of list, name brand fame, etc.

Above the fold

The part of an email message or Web page that is visible without scrolling. Material in this area is considered more valuable because the reader sees it first.


Email automation refers to email campaigns that automatically send when a person does something that is set to trigger these automated emails.

ARPES [average revenue per email sent]

ARPES is calculated by dividing the sum total of revenue generated by an email marketing campaign by the total number of emails sent over the course of that campaign.

Average revenue per user [ARPU]

A close cousin of ARPES (average revenue per email sent), ARPU is a metric aimed squarely at a mailing list’s subscribers and how they respond to a company’s overarching email marketing strategy. It is calculated by dividing the sum total of revenue generated by an email marketing campaign by the total number of subscribers on the mailing list for that campaign.

A/B Split Test

An optimization technique that divides a list in two then sends a different email to each half of the list to see which variation converts best.

Acceptance Rate

The percentage of email messages that a mail server accepts.

ALT tags

Part of the code that creates an image. ALT tags contain text that describes the image.


Email message that notifies subscribers of an event or special price.

Affirmative consent

An active request by a reader or subscriber to receive advertising or promotional information, newsletters, etc.


A marketing partner that promotes your products or services under a payment-on-results agreement.

Animated Gif

An image that changes, like animation but with only a couple of frames. Animated gifs can be used in emails.


A file that is attached to an image. Not recommended for promotional emails. Malware is often sent from unknown senders as an email with an attachment.


As in email authentication. This is the data encoded into every email message. It tells where the email came from and which servers relayed the information. This data is used, in part, to decide whether the email is delivered to the inbox, or filtered as spam.


An automated message or series of messages. Sometimes called a “drip campaign”.

Behavioral Email

A way to customize which email messages a subscriber get based on how they have behaved in the past.

Bayesian filter

An anti-spam program that evaluates header and content of incoming email messages to determine the probability that it is spam


A list of email senders of bad repute. Being on a blacklists means a sender’s email messages may not get to the inbox at all.

The body

Is the main part of any email. It encompasses the copy, images and any attachments of the email (although some of these may be displayed elsewhere).


A severe email deliverability problem. A block is when none of a sender’s email messages get through.


A message that doesn’t get delivered promptly is said to have bounced. Emails can bounce for more than 30 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.

Bounce message

Message sent back to an email sender reporting the message could not be delivered and why. Note: Not all bounced emails result in messages being sent back to the sender. Not all bounce messages are clear or accurate about the reason email was bounced.

Bounce Rate

Can be measured as hard bounces, soft bounces, or both. Bounce rate is shown as a percentage. It measures how many emails have been returned by a email service. A bounce can happen because a subscriber’s email address either no longer exists, their inbox was full, or because a server was unavailable.


Similar to an “email blast”. When you send out the same email message to everyone on your list all at once.

Bulk Email Service

Allows you to send email communications to large lists of multiple recipients by incorporating email into your applications. You can send one email to many people, or a unique email to each person on your list with a bulk email service.Commonly, bulk email is used for newsletters or marketing email. If you have a list of customers or prospects, you can send them content relevant to their business or interest, from a single application. A bulk email service allows you to send to any list, regardless of its size. The frequency at which you send is entirely up to you, and should be based on what the recipients expect. Your engagement data, including spam reports, unsubscribes, and open and click rates, will tell you whether your message is hitting the mark.

Bulk Folder

The polite term for the spam folder.

Call to Action [CTA]

A word or phrase used to incite the subscriber to do something. Call to action copy appears on order buttons, for example. It can also appear as linked text in an email.


An email server function that forwards all questionable email to a single mailbox


The 2003 American law designed to reduce spam from commercial emails.


help organize your email analytics by enabling you to tag emails you send by topics you define.

Challenge–response [C/R]

System is a type of filter that automatically sends a reply back with a request to the sender of an incoming e-mail. In the reply, the sender is asked to perform an action to ensure delivery of the original message. The action to be performed is easy to do if you’re an individual, but requires a lot effort if performed in large numbers, in this way effectively filtering out spammers

CASL [Canadian Anti-Spam Law]

The Canadian equivalent of CAN SPAM law. CASL went into effect in June 2014.


A very short looping movie that can be embedded into emails and on websites.


A statistic that indicates that your email recipient has clicked on a link included in the body of your email.

Click-through & click-through tracking

When a hotlink is included in an email, a click through occurs when a recipient clicks on the link. clickthrough tracking refers to the data collected about each click through link, such as how many people clicked it, how many clicks resulted in desired actions such as sales, forwards or subscriptions.

Click Through Rate [CTR]

A percentage that shows how many subscribers clicked on a link in your emails. Related to “unique click through rate”, because some subscribers will click more than once.

Click-to-Open Rate

A percentage of how many of the people who opened your email then clicked on one of the links in that email.

Commercial email

Email whose purpose, as a whole or in part, 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.

Complaint Rate

A percentage of how many subscribers marked an email message as spam.


An acknowledgment of a subscription or information request. "Confirmation" can be either a company statement that the email address was successfully placed on a list, or a subscriber's agreement that the subscribe request was genuine and not faked or automatically generated by a third party.


All the material in an email message except for the codes showing the delivery route and return-path information. Includes all words, images and links.

Confirmed opt-in

Inexact term that may refer to double-opt-in subscription processes or may refer to email addresses which do not hard bounce back a welcome message. Ask anyone using this term to define it more clearly.

Contact List

Another term for your subscriber list or “mailing list.


Represents the total number of wonderful folks who performed the desired action or outcome that the email marketer originally hoped to achieve when crafting and sending a marketing email

Conversion Rate

A percentage that shows how many people completed a specific action. A 5% conversion rate for orders from an email campaign means five out of one hundred people you sent an email to placed an order.


Arrangement in which companies collecting registration information from users (email sign-up forms, shopping checkout process, etc.) include a separate box for users to check if they would also like to be added to a specific third-party list.


An email message's copy and any graphics.

CPA [Cost per Action also can be Acquisition]

A method of paying for advertising, or calculating results from non-CPA marketing.

CPC [Cost per Click]

A method of paying for advertising. Different from CPA because all you pay for is the click, regardless of what that click does when it gets to your site or landing page.

CPM [Cost Per Thousand]

An advertising or list management term that means “Cost per thousand”. Is sometimes interchanged with “CPT”.


A markup language used to design emails and web pages. Stands for “Cascading Style Sheets”.

Cross-campaign profiling

A method used to understand how email respondents behave over multiple campaigns.

Dedicated Server

An upgrade from a shared server. Refers to the computer server used to send email campaigns.

Delivery tracking

The process of measuring delivery rates by format, ISP or other factors and delivery failures (bounces, invalid address, server and other errors). An inexact science.


The art and science of getting emails from a sender all the way to subscribers’ inboxes.

Delivery Rate

What percentage of emails sent from the sender actually reach subscribers’ inboxes.


Another way to say “send”, as in “the email campaign was deployed”.

Denial-of-service attack [DOS]

An organized effort to disrupt email or Web service by sending more messages or traffic than a server can handle, shutting it down until the messages stop.


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.

Discussion group

An email service in which individual members post messages for all group members to read ("many to many.") In contrast, a newsletter is a "one to many" broadcast, where comments by members or subscribers go only to the message sender. Aka by the trademarked name Listserv.

Domain-based Message Authentication Reporting and Conformance [DMARC]

Is an additional layer of email authentication that builds on the two previous authentication methods Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM). First and foremost, both SPF and DKIM must be implemented before a DMARC policy can be put into place.

DKIM [DomainKeys Identified Mail]

An email authentication technique that links a domain name to an email message. Used to verify an email's authenticity and to increase deliverability rates.

Double Opt-in

As opposed to single opt-in. A way to process new email subscriber requests that requires those subscribers to confirm their email address before they are on list.

Drip Marketing

Usually refers to automated marketing that sends a series of messages to prospects over time. Autoresponders are a type of drip marketing.


is a named Internet address that resolves to the numbered Internet Protocol (IP) addresses computers use to connect. Examples:,, Simply put, it’s the web address your users type into their browser to learn about your company.


Occurs when our systems identify that a message is sent to an email address that is already listed on one of the suppression lists: Bounces, Unsubscribes, Spam reports and Invalid Emails. If an email is already on one of the lists mentioned above, our systems automatically drop the email in order to protect your Sender Reputation.

Dynamic Content

A personalization technique that swaps different content into pre-defined parts of an email message based on a subscriber's’ preferences, location or past behavior.


Email Change of Address. A service that tracks email address changes and updates.

Effective rate

Metric that measures how many of those who opened an email message clicked on a link, usually measured as unique respondents divided by unique opens.

Email Analytics

All the technologies and metrics used to measure email programs.

Email Appending

Sometimes called a “data overlay”. A list-enhancement technique where email names are appended unto a customer data, usually by a database company that has those customers’ email addresses.

Email Campaign

Each time you send a promotional message to your subscribers, you’re sending a campaign. The term applies to the list select you’re sending to, the creative, and the results of each email deployment.

Email Client

The software that a subscriber views their email messages in.

Email blast

Is a single email message that is sent to a large group of recipients. Email blasts are no longer an email marketing best practice. Email marketers should segment their lists and send targeted messages to their subscribers. All email blasts need to follow the CAN-SPAM Act, include an unsubscribe link, and accurately identify the person or business that is deploying the email.

Email Domain

The domain name, website or URL that an email is sent from. Typically, this is your company’s primary domain name.

Email filter

A software tool that categorizes, sorts or blocks incoming email, based either on the sender, the email header or message content. Filters may be applied at the recipient's level, at the email client, the ISP or a combination.

Email Harvesting

The spammer’s technique of stealing people's email addresses by finding those addresses online and then adding them to a list without the email address owner’s permission.

Email marketing software

Is service-based software that marketers use for email marketing. This software can be used for a variety of different purposes, from growing a list of email subscribers, to designing and building customized email templates, to creating segmented lists for more targeted, relevant emails to be sent. With a variety of services, resources, and tools, the software allows marketers to do much more than simply send emails.

Email marketing template

Is a pre-made template that gives marketers a starting point for their email. Templates are often referenced when marketers don’t want to start from scratch and build out an email wireframe with custom coding from the ground up. Email marketing templates provide a general framework to start from, while still allowing for vast personalization of color, photos, text sizing, branding, and fonts–often times via simple drag and drop features within an email builder.

Email marketing Tools

are tools that marketers use to create, send, test, optimize and report on their email campaigns. An email marketing tool could be a specific tool related to email marketing like an email subject line generator, or an inbox placement testing tool, or a suite of tools that enables a marketer to do all their email marketing end-to-end.

Email marketing

Benchmarks are metrics a business or organization uses to gauge the success of their email marketing efforts over time. Often times, organizations study both internal benchmarks and industry-wide benchmarks for performance, and these may change and evolve over time. Common email marketing benchmarks include open rate, click-through rate, conversion rate, bounces, unsubscribes.

Email newsletters

Are an email communication sent out to inform your audience of the latest news, tips, or updates about your product or company. They are often used for a variety of purposes–and they come in many different forms. Some are weekly digests of content, some are quarterly organization updates, and others promote new products. The point of email newsletters are to keep subscribers connected, engaged, and informed about what’s new with the organization or business.

Email Prefix

The portion of the email address to the left of the @ sign.

Email vendor

Another name for an email broadcast service provider, a company that sends bulk (volume) email on behalf of their clients. Also email service provider (ESP).

Email Phishing

A fraudulent email sent from a spammer that says something has gone wrong with a critical account and asks the recipient to give their bank account login information or other sensitive information via a link in the email. The spammer then collects the information the unknowing email recipient has given them.

Email Queue

The email messages that are all set up and ready to go, but are waiting for your email service provider to actually deploy them.

Email Shares

A numerical count of how many times your emails have been shared or posted on social media. Can be both overall shares and unique shares.


Special characters that create tiny images that you can embed in an email subject line, or anywhere else.


An umbrella term that covers every possible interaction an email subscriber can have with your message, like opens, clicks, shares and more.

Enhanced whitelist

A super-whitelist maintained by AOL for bulk emailers who meet strict delivery standards, including fewer than 1 spam complaint for every 1,000 email messages. Emailers on the enhanced whitelist can bypass AOL 9.0’s automatic suppression of images and link

Event triggered email

Pre-programmed messages sent automatically based on an event such as a date or anniversary.

ESP [Email Service Provider]

The company that provides software and hardware to manage your list and deploy and track your email messages.


A count of how many times one of your subscribers forwarded a message you sent them to someone else.

Feedback loop

Is the process by which an ISP forwards emails reported as spam (see complaint) for immediate removal by the sender.

False positive

A legitimate message mistakenly rejected or filtered as spam, either by an ISP or a recipient's anti-spam program. The more stringent an anti-spam program, the higher the false-positive rate


An area at the end of an email message or newsletter that contains information that doesn’t change from one edition to the next, such as contact information,the company’s postal address or the email address the recipient used to subscribe to mailings. Some software programs can be set to place this information automatically.


Whatever appears in the email recipient's inbox as your visible "from" name. Chosen by the sender. May be a personal name, a brand name, an email address, a blank space, or alpha-numeric gobbledegook. Note - this is not the actual "from" contained in the header (see below) and may be different than the email reply address. Easy to fake. Aka Email Friendly Name.


The documentation: that accompanies the body of an email message, the header contains information on the email and the route it has taken across the Internet. Email readers display the “to” (identity of the recipient) and “from” (identity of the sender) in the inbox.


Is the standard markup language used to describe the content and structure of web pages, emails and applications. It is a cornerstone internet technology, and without it the world would be plunged into eternal darkness and chaos.

Google Analytics

The free, most-widely used tracking software provided by Google. Google analytics can track interactions with an email message, and how people behave once they arrive on your website.


An action taken by major ISPs like AOL, Gmail and Comcast where an inactive email is changed into a spam trap.

Grey Mail

A polite term that refers to email messages subscribers are no longer interested in, but have not unsubscribed from and would not mark as spam.

Goodbye message

An email message sent automatically to a list member who unsubscribes, acknowledging the request. Always include an option to re-subscribe in case the unsubscribe was requested accidentally.

Hard Bounce

When an email cannot be delivered to someone’s inbox because that email account no longer exists or the email server was down.


The top section of an email message. Can also refer to top lines of code in an email. These first lines of code include important information about the attributes of an email message, but they are not seen by average users.

Honey Pot

An email address that also serves as a spam trap. A honey pot is specifically an email address left in plain site on a website so it can be harvested by a spam bot. As soon as the email address is used, the anti-spam entity flags the sender as a spammer.

House List

Your core list of email subscribers.


A markup language that allows email coders and designers to do cool things like email carousels, video embeds, and more.

Image Blocking

The default setting in many email clients that blocks images from being shown. Can be turned on or off by the email subscriber, but can also wreak havoc on an email’s appearance.


Internet Message Access Protocol, a standard protocol for accessing email from a server.


The subscribers on your list who have not opened or clicked in a month or more.

Inbox Placement Rate

A percentage that expresses how often the emails you send actually reach subscribers’ inboxes.

IP warming

Is the gradual process of establishing a reputation as a legitimate email sender in the eyes of ISPs (Internet Service Providers). When an ISP observes email suddenly coming from a new or “cold” (recently dormant) IP address, they will take notice and immediately begin evaluating the traffic coming from that IP.

IP Address

A unique string of numbers separated by periods that identifies computers across networks. IP address are used as identifiers of email senders from all over the world.

ISP [ Internet Service Provider ]

A company that provides Internet access to individuals or businesses. ISPs also usually offer email accounts, and thus are in many ways the gatekeepers of the bulk of email accounts.

Landing Page

Where a subscriber will go after they click on a link in your emails. Can also apply to where someone goes after they click on an advertisement, or any other content format online.


What happens when links go bad over time, either because a Website has shut down or a site has stopped supporting a unique landing page provided in an email promotion.


The list of email addresses to which you send your message. Can be either your house list or a third-party list that sends your message on your behalf.

List Broker

A professional who networks and makes deals with list owners and email marketers. List brokers typically take a percentage of however much the email marketer is paying to buy or rent a list.

List Churn

List churn is an umbrella term for all the ways people can disengage from a list. That could be changing their email address, not opening emails anymore, or any other cause of inactivity.

List Fatigue

Declining engagement that occurs over time after an email list has been mailed to too frequently.

List Growth

How quickly you are adding new subscribers to your list. List growth also takes list churn into your account. So list growth refers to how much larger your list is getting, even after the effects of list churn.

List Hygiene

How well your list’s information is kept up to date. This includes removing unsubscribes and inactives.

List Owner

The organization or individual who has gathered a list of email addresses. Ownership does not necessarily imply "with permission.

List Sale

The actual purchase of a mailing list along with the rights to mail it directly. Permission can only be "sold" if the subsequent mailings continue to match the frequency, brand name, content, and "from" of the past owner's mailings -- and even then this is a somewhat shaky procedure on the spam-front. You are in effect buying a publication, and not just a list.

List Rental

An arrangement between an email marketer and a email list owner where the list owner accepts an email message from the email marketer and then sends that email to their list. The list owner will deploy the marketer’s email.

Lotus Notes (now ``IBM Notes``)

Developed in 1989 by the Lotus Development Corporation, Lotus Notes is a legend in email marketing circles for being the worst email client ever. It appears to have been specifically designed to make the lives of email marketers resemble hell on earth as closely as possible.

Mail Merge

Is a process to create customized emails, letters, and documents from a generic form or template. The original document contains static text with placeholders for substitutions for elements like names, addresses, emails, or other individualized or unique information.

Mail loop

A communication error between two email servers, usually happening when a misconfigured email triggers an automated response from the recipient server.


Sometimes shortened to msgid, is a unique identifier assigned to individual email messages by the email server responsible for sending the message.


Mail Transfer Agent. A computer that forwards email from senders to recipients (or to relay sites) and stores incoming email.


Mail service provider, such as Hotmail.

Multi-part MIME

Also known (confusingly) as an "email sniffer." Message format which includes both an HTML and a text-only version in the same message. Most (but not all) email clients receiving messages in this format will automatically display the version the user’s system is set to show. Systems that can’t show HTML should show the text version instead. This doesn’t always work — in particular for many Lotus Notes users. Also, no data, except HTML open rates and possibly link click tracking, is transmitted back to the sender regarding which version a recipient wound up viewing.


Mail Exchange Record

Mass email marketing

Is the practice of creating a single message for a large group of subscribers. This is not a common best practice in the world of modern email marketing. Today, most marketers prefer to send more personalized emails that cater to the interests of different segments within their lists of subscribers, as tailoring to the individual is proven to be more effective than bulk email. Marketers are accomplishing this at scale by using the simplicity and scale of marketing automation.

Marketing Automation

The marketing strategy of defining communications to different customer segments, then setting those messages to go out automatically. Autoresponders are an example of marketing automation.

MIME [Multi-Purpose Internet Mail Extensions]

This is an extension of the original email protocol that allows people to send different file formats back and forth.

Open relay

An SMTP email server that allows outsiders to relay email messages that are neither for nor from local users. Often exploited by spammers and hackers.

Open rate

The number of HTML message recipients who opened your email, usually as a percentage of the total number of emails sent. The open rate is considered a key metric for judging an email campaign's success, but it has several problems. The rate indicates only the number of emails opened from the total amount sent, not just those that were actually delivered. Opens also can't be calculated on text emails. Also, some email clients also users to scan message content without actually opening the message, which is falsely calculated as an open.


A marketing technique of educating new customers or clients in your business’s strengths and features. Welcome emails are common examples of onboarding.

Opt-in Box

The set-off areas on your website where people can opt-in to your list. Note that the opt-in form itself is embedded into the web page for opt-in boxes.

Opt-in Rate

What percent of your website visitors (or landing page visitors) sign up for your email list.


When people unsubscribe from your email list.


An email recipient who got your message via forwarding from a subscriber. (Some emails offer "forward to a friend" in the creative, but the vast majority of pass-alongs happen using email clients, and not that tech.) Pass-alongs can affect the formatting of the email, often stripping off HTML. Also known as viral.

Permission-based email marketing

Asking for, and obtaining, permission to email subscribers is the basis of permission marketing. Most often, subscribers will check a box to give you consent (permission) to send them emails.


Post Office Protocol, which an email client uses to send to or receive messages from an email server.


A form of identity theft in which a scammer uses an authentic-looking email to trick recipients into giving out sensitive personal information, such as credit-card or bank account numbers, Social Security numbers and other data.

Pre-Header Text

Part of an email message that is always text and appears right below the subject line when viewed in an inbox.


A marketing strategy that customizes marketing messages based on customer or client information. Dynamic content is a personalization technique, as is inserting each subscriber’s name into the subject line.

Plain Text

As opposed to “an HTML email”. Plain text is an email layout or formatting that uses no markup or layout in the email. The entire content of the email is just lines of text, with the call to action hyperlinked to a landing page.

Preference Center

A page on your website or a page hosted by your email service provider. Preference centers let subscribers edit their information and control how often they receive emails from you.

Preview Pane

The top section of an email that is visible from the inbox dashboard view. Used less now than in years past.

Privacy Policy

Every website is required to have a privacy policy. A privacy policy explains to website visitors and to email subscribers how their information is collected and used.

Promotional Emails

As opposed to transnational emails. Emails sent out to announce or promote a product or service.

Promotions Tab

The recently-added Gmail feature that moves most promotional emails out of the dashboard view of the inbox and into the promotions tab.


Where an email message goes after you send it but before the list owner approves it or before the list server gets around to sending it. Some list software allows you to queue a message and then set a time to send it automatically, either during a quiet period on the server or at a time when human approval isn't available.

Rate Limiting

There are limitations to delivery rates imposed by recipient mail servers. Exceeding these limitations results in a practice referred to as throttling. Throttling in terms of email means that a recipient mail server has accepted all the mail it is willing to accept from your IP for a certain period of time.


The process where someone not only opts in to your email program but provides some additional information, such as name, address, demographic data or other relevant information, usually by using a Web form.

Relationship email

An email message that refers to a commercial action -- a purchase, complaint or customer-support request -- based on a business relationship between the sender and recipient. Generally are not covered by CAN-SPAM requirements.

Re-engagement Campaign

An email campaign sent to try to get inactive subscribers to re-engage.


How an email message appears in each subscriber’s inbox.


The email marketing technique where you send the same email a second time to try to get more people to respond to it.

Responsive Design

Design that will render properly on mobile devices, or any other device.

Rich Media

Creative that includes video, animation, and/or sound. Rich-media emails often collect high open and click rates but requires more bandwidth and are less compatible with different email clients than text or regular HTML email-format messages. Some mailers also consider transactional email "rich".

Reputation Monitoring

You will notice on your Account Overview page you will see your IP reputation score, which will be somewhere from 0% to 100%. This score will go up or down based on your bounce, block, spam and invalid rates.

Revenue Per Email Sent

A metric that shows how much you’ve earned per each email you sent out.

Scheduling emails

Allows the ability to have the email send at a certain time.


A spamming technique. Scraping is when scraping software goes out on the Internet to find any email address it can. This is why many email addresses on contact forms use formatting like “Barbara (at) yahoo dot com”. The site owner hopes the spelled-out email address will confuse scraper bots.


The email marketing technique of breaking a list up into different segments. You can segment a list dozens of different ways, including by subject preferences, last opened date and more.


A segment of a list determined by any number of attributes, such as source of name, job title, purchasing history, etc. CPM list renters pay an additional fee per thousand names for each select on top of the base list price.

Selective Unsubscribe

An unsubscribe mechanism that allows a consumer to selectively determine which email newsletters they wish to continue receiving while stopping the sending of others.

Sender ID

The informal name for a new anti-spam program combining two existing


Sender Policy Framework and CallerID. SenderID authenticates email senders and blocks email forgeries and faked addresses.

Sender Policy Framework [also SPF]

A protocol used to eliminate email forgeries. A line of code called an SPF record is placed in a sender’s Domain Name Server information. The incoming mail server can verify a sender by reading the SPF record before allowing a message through.

Sender Name

Also referred to as the “from” name, this is the part of your emails where a subscriber can see who’s sent them the email message. Sender name is visible from the inbox. In some email clients it is more prominent than the subject lines.

Sender Score

An email deliverability metric assigned by the company ReturnPath. A SenderScore of 70 is about average.

Shared Server

As opposed to a dedicated server. The server your email messages are sent from.

Sent emails

Number of email names transmitted in a single broadcast. Does not reflect how many were delivered or viewed by recipients.


A line or two of information found in the closing of an email, usually followed the sender’s name. Signatures can include advertising information, such as a company name, product, brand message or marketing call to action (subscribe to a company newsletter with the email subscribe address or Web registration form, or visit a Website with the URL listed)

Signature File

A short default file at the end of email messages. Signature files usually include contact information.

Single Opt-in

As opposed to double opt-in. A way of letting new email subscribers opt-in without requiring that those subscribers confirm their email addresses first.

SMTP (Simple Mail Transfer Protocol)

The language or "protocol" servers use to talk to each other as they send emails around the world.

Soft Bounce

As opposed to a hard bounce. Less severe than a hard bounce. A soft bounce is when an email cannot be delivered because the inbox is full or the server is temporarily unavailable.

Solo Ads

Used more in affiliate marketing than B2B or B2C marketing. A solo ad is when an email marketer pays to have a list owner send a message to their list. Similar to list rental.


There are two definitions of spam. The first is the legal definition of spam, as defined by the CAMSPAM Act and Canada’s CASL legislation. The other definition is from subscribers, who consider spam to be any email message they don’t want.


A blacklist and IP-address database, formerly privately owned but now part of the email vendor Ironport. Many ISPs check the IP addresses of incoming email against Spamcop’s records to determine whether the address has been blacklisted due to spam complaints

Spam Trap

An email address used by anti-spam entities to trap spammers.


Anyone who sends unwanted emails.

Sponsorship swap

An agreement between email list owners, publishers or advertisers to sponsor each other's mailings or newsletters for free.


The practice of changing the sender's name in an email message so that it looks as if it came from another address

Split testing

Is the act of sending out numerous versions of emails following the same theme but containing variations in text, composition, and appearance, then tracking the results based on a number of success metrics to determine the most effective combination of elements for a particular campaign.

Statistical Relevance

A term used in A/B split-testing. Before you call a winner in an A/B split test, you need to know your results are statistically valid.

Subject Line

An email message’s equivalent of a headline, or title.


The people who have signed up to receive your email messages.

Suppression File

A list of email addresses that should not be mailed to. Some companies maintain a global suppression file. Even marketers in separate divisions may not mail to a global suppression file.


A necessary step before sending an email campaign or newsletter. Many email clients permit you to send a test email before sending a regular email newsletter or solo mailing, in which you would send one copy of the message to an in-house email address and then review it for formatting or copy errors or improperly formatted links. Email marketers should also send a test campaign to a list of email addresses not in the deployment database to determine likely response rates and how well different elements in the message perform.


Similar to segmenting an email list. A “targeted list” usually means a list of email subscribers who have very similar interests or behaviors.

Thank You Page

The page new subscribers see after they’ve entered their email address into the opt-in form and clicked the subscribe button.


An email deployment technique. Throttling sends email messages out in batches, instead of all at once. This improves deliverability rates and server load management.

Transactional Emails

As opposed to promotional emails. Transactional emails are emails sent to confirm orders, reservations, and anything else. They have higher engagement rates than promotional emails.

Triggered Emails

A form of marketing automation. Triggered emails are pre-scheduled by the marketer. They are sent whenever a specific event happens or a specific period of time has passed. Birthday emails would be an example of triggered emails.

Two factor authentication

Two-Factor Authentication (also known as: 2FA, two step verification, or TFA) is an extra layer of security that is known as “multi factor authentication” that requires not only a password and username but also something that only that user has on them, i.e. a piece of information only they should know or have immediately at hand such as a physical token, a phone application, or a device.

UCE [unsolicited commercial email]

A fancy term for spam.

Unique Clicks

This is how many individual subscribers have clicked on links in your emails. It is more specific than overall click-through rate, which just shows how many times your emails were clicked.

Unique Opens

Some subscribers will open an email more than once. Unique opens shows how many individuals have opened your emails, not just how many times your emails were opened.

Unsubscribe Rate

A percentage that shows how often people are opting out from your email campaigns. Unsubscribe rate is usually (but not always) calculated on a campaign by campaign basis


A program that determines an email came from the sender listed in the return path or Internet headers; designed to stop email from forged senders.

Video e-mail

An email message that includes a video file, either inserted into the message body, accessible through a hotlink to a Web site or accompanying it in an attachment (least desirable because many ISPs block executable attachments to avoid viruses).

Viral email marketing

Is an approach that strives to get emails shared quickly and between many people. It is often aimed at creating emails that are quickly forwarded and shared on social channels in a word-of-mouth manner. However, there are no surefire tactics for creating a truly viral email.

Welcome emails/welcome series

An email message or a series of email messages sent to new subscribers.

White List

Email marketers often encourage subscribers to “whitelist” their emails. A subscriber whitelists the email by marking it as important or moving it to an appropriate folder in their inbox.

White hat sender

Is a sender or company who only sends email to those recipients who have given express permission to receive email from the sender. Put simply, white hat senders always strive to “send the right message, to the right person, at the right time, with the right frequency.”


Chapter: 8