Email Marketing Glossary of Terms

Common terms and expressions you'll need to know in order to fully understand your email metrics.

Posted by Dan Mattson on October 14, 2017

As a small business owner, you naturally want every one of your advertising dollars to count. Email Marketing is one of the most cost-effective ways to reach a large volume of prospective customers. But chances are that you don’t have the time to stay up to date on Email Marketing terminology and functionality.

We have created the glossary below to help you become more familiar with the common terms associated with Email Marketing; this way, you can comfortably move forward in using this powerful strategy to grow your business.

Above The Fold

There can be no thought of finishing for ‘aiming for the stars.’ Both figuratively and literally, it is a task to occupy the generations. And no matter how much progress one makes, there is always the thrill of just beginning.

There can be no thought of finishing for ‘aiming for the stars.’ Both figuratively and literally, it is a task to occupy the generations. And no matter how much progress one makes, there is always the thrill of just beginning.

Acceptable Spam Report Rate (ASRR)

The rate at which your emails recipients can report your email as spam before your reputation as a sender is damaged. The current ASRR is 0.1% (or 1 in every 1,000 emails). Anything over this amount will generate a warning against your outgoing mail server.

Acceptance Rate

The rate at which your audience’s incoming mail server accepts your outbound emails. Please note that just because the emails are accepted, this does not mean they will go to the Inbox (they may be filtered as spam) or may never be opened.

Black List

A list of IP addresses known for sending spam emails. Please refer to Acceptable Spam Report Rate for further information.

Bounce Rate

The rate at which the emails you send are unable to be delivered for any reason. Bounce rates below 5% are generally expected and acceptable. Please see Hard Bounce and Soft Bounce for further information.

Bulk Mail

Email sent to a large number of recipients where every message contains the same information. For example, one marketing email sent to 1,000 email addresses at once.


Enacted in 2003, this law enables consumers to opt out of receiving unsolicited emails from advertisers. The law provides for legal consequences to prevent a company from continuing to email a person who has registered a complaint. This acronym stands for “Controlling the Assault of Non-Solicited Pornography And Marketing.” The full text of this law is located here: CAN-SPAM Act of 2003.

Clicks Per Delivered

The rate of clicks on links within an email generated by delivered emails.

Clicks Per Open

The rate of clicks as divided by the number of emails that are both delivered and opened to be read.

Cost Per Thousand

This is the rate set for email lists that are for rent or for sale. For example, a curated list of 1,000 verified email addresses and is rented or sold for $0.25 per address has a Cost Per Thousand of $250.00.

Click Through Rate

The percentage of people who open your email and click on a URL (link) contained within it based against the number of emails sent out on that particular campaign. The click through rate only considers unique clicks and does not take repeated clicks from the same computer into the equation.

Cost Per Thousand

This is the rate set for email lists that are for rent or for sale. For example, a curated list of 1,000 verified email addresses and is rented or sold for $0.25 per address has a Cost Per Thousand of $250.00.

Conversion Rate

This is a major measure of your email campaign’s success. Conversion refers to the prospective customer moving from simply an email recipient to someone who is actively seeking to learn more about your company or product, or become a customer. The conversion rate is the percentage of people who respond to your email’s call to action (“Call now,” “Click here,” etc.). The higher the conversion rate, the more interest you have generated.

Dedicated IP

This is an IP (Internet Protocol) address you set aside for your marketing purposes. If you are doing heavy email marketing, it is wise to have a dedicated IP for your outgoing marketing messages because if you become blocked for any reason, it will not affect the rest of your business operations, only the dedicated IP.


The act of performing housekeeping on your email marketing lists by consolidating contact information and removing duplicate contacts. You can easily do this with tools in your Excel contact spreadsheet or your contacts database program and prevents you from over-emailing your prospects.

Double Opt-In

A method for users to confirm their permissions for you to send them marketing information that requires them to respond to a confirmation email or click on a second confirmation checkpoint during the opt-in process. This helps ensure your recipients are real people and not bots and helps to prevent the sending of unwanted emails.

Email Campaign

A progressive series of emails sent to your prospects that gradually becomes more personalized and nurtures the business/prospect relationship to help generate future purchases

Email Filter

A tool in almost every email program that allows the end user to block email based on several criteria, including sender name, sender address, domain name, subject line, or IP address. Filtered messages may go to the Spam Folder or simply be deleted before ever reaching the Inbox.

Email Sponsorship

Sometimes referred to as a 'Solo Ad'...
Ad space contained in the body of marketing emails that other advertisers purchase. For example, you can sell space in your marketing emails to other organizations and their ads will go to your customers, generating revenue for your company and your sponsor.

False Positive

The instance where a legitimately opted-in email is blocked as spam by an email program.

Hard Bounce

A notification returned to the sender of an email that the desired recipient’s email address is permanently disabled, does not exist, or is blocked.

Honey Pot

An email address used by an organization that is set up for the sole purpose of collecting spam and identifying the senders of spam.

House List

Your personally curated list of email subscribers who have opted in to receive messages from you.

HTML Email

Email that contains HTML coding, making it possible to insert graphics, sounds, animations, and other interactive features into the body of the message.

IP Warmup

The process of sending a small number of emails out from a dedicated IP address, then gradually building the number of emails sent to coax a good reputation rating out of automated inbound mail servers.

Landing Page

The web page your email recipients will land on when they follow a link in your email. The landing page should contain highly relevant information to your email, including your contact details and information about the product or service. This information should all be visible without the user having to scroll down or click another link.

Lead Nurturing

A passive yet highly effective sales tactic of building relationships with your prospective customers without taking a forceful approach to sales. Rather, lead nurturing keeps contact with the customer, allowing them to make the decision when they are ready to buy.

Levels Of Authentication

An automated means of establishing the identity of an email sender and verifying they have permission to send bulk emails from the originating domain.

List Fatigue

The state of over-emailing your prospect list with too many of the same messages in too short of a time frame. Also called List Burnout.

List Hygiene

The process of going through your email lists to identify and remove bouncing email addresses, duplicate addresses, and those that have opted out of your marketing.

List Segmentation

The act of dividing your email list into more targeted sections. For example, East Coast and West Coast recipients may need to receive different offers. Because this makes your emails more relevant to a specific demographic of users, your spam rate will decrease while your response rate will increase.

Open Rate

The percentage of emails opened out of those delivered to the Inbox.


The process in which a user gives you permission (opts in) or denies you permission (opts out) to send them email marketing messages. It is imperative to take your opt-outs seriously, as there are legal ramifications for not doing so.


Marketing emails sent to recipients using fields for known information, such as their name and location. These are meant to appear as if the message is only being sent to the single user.

Plain Text Email

An email with no HTML or other coding. While there can be no graphics displayed in the email, this format is preferred for mobile devices.

Privacy Policy

A company’s clearly defined terms of use for customer information. It should tell the user what information your site collects from them (including name, email address, IP address, geographic location, and browsing history), whether or not it will be sold, how long the information is kept, and how their data is used.

Read Length

Also called Open Length, the length of time a user keeps an email open before closing or deleting it. Keeping the body of your email clear and concise will allow the user to see and retain more information in a shorter amount of time. Emails that are too long (or that take more than 4 minutes to read) are less likely to have the staying power you desire.

Retention List

The list of email addresses your company keeps as your most valuable email marketing asset because these contacts have either used your company before or have directly expressed interest in hearing from you, for example with special sales or promotional emails.

Sender Score

Used by a free program called Return Path to generate a rating of 0-100 on outgoing mail IP addresses. Mail servers run a check on your IP address against this score to decide if they should deliver it, send it to Spam, or refuse it. You want to maintain a score of 90 or above to guarantee a high delivery rate.

Shared IP

An IP address used by several departments or companies to send their marketing emails. This is a less expensive option than having a dedicated IP; however, if one sender generates too many spam reports, this can prevent everyone using the shared IP from sending email.

Signature File

The text block inserted at the end of an email which contains the sender’s contact information (Name, Company, Phone, Fax, Email, Address), and often their company slogan and/or an additional call to action.

Single Opt-In

A means of giving permission for a company to send them promotional emails. This method does not require the user confirm their email preferences, therefore any person, company, or bot can sign up any number of email addresses to receive marketing emails. To avoid this and ensure your messages are going to real people, a Double-Opt In method is preferred.

Soft Bounce

An auto-response message returned to the sender of an email that the mail cannot be delivered due to a temporary condition, such as a server down or a full Inbox.


Email messages sent in bulk to recipients who did not give permission to the sender to send them email. These unsolicited messages are typically irrelevant to the user’s interests or needs.

Spam Trap

An email address that was previously valid and deliverable but has been abandoned. These email addresses will initially generate a hard bounce automated response. If messages continue going to the address from the same IP or domain, the inbound mail server will stop responding with bounce messages and will allow the emails. At this point, the inbound server will turn the email address in question into a spam trap. Once the auto-responses cease, every subsequent email received will be reported as spam. For this reason, it is vital for email marketers to keep a clean list of email addresses.


A list of IP addresses approved by the recipient to send email to their address. If an IP address is whitelisted, email coming from that address will never be blocked or sent to the Spam folder.