Email Marketing Terms You Should Know: A-Z Glossary

Jul 21, 2023

Whether you’re brand new to email marketing or a seasoned professional, you’re likely to come across email marketing terms that sound more like a foreign language than something that is critical to your job.

We’ve all been there. This glossary aims to be your trusty guide as you demystify the jargon of email marketing. 

From basic terms like “Open Rates” and “Subject Line” to more advanced terms like “Split Testing” and “Segmentation”, the language of email marketing is packed with key terms that shape our strategies, guide our decisions, and determine our successes.

These aren't just fancy words that were created by email marketers to sound intelligent — they are terms that truly help us understand our audience, track campaign performance, and drive the growth and success of our businesses. And to top it off, some of them have legal repercussions, too. 

This email marketing glossary will be breaking down these key terms one by one, providing clear definitions and actionable insights. We'll shed light on what these terms actually mean, why they're important, and how you can use them to your advantage.

Email marketing terms you absolutely need to know. A-Z. 

Let’s dive in.

Email marketing terms you need to know

A/B Testing 

A method used to compare two versions of an email to determine which performs better.

Above the Fold

The portion of the email that is visible without scrolling.

Acceptance Rate

The percentage of emails sent that are successfully accepted by the recipient's mail server, regardless of whether they land in the inbox or spam folder.


A file sent along with an email message.


An automatic email or sequence of emails sent when a trigger event occurs.


A list of IP addresses or domains that are suspected of sending spam and are therefore blocked from sending emails to certain servers or recipients. Being on a blacklist can severely hinder email deliverability.

Bounce Rate

The percentage of your total emails sent that could not be delivered to the recipient's inbox.

Buyer Persona

A detailed, semi-fictional representation of an ideal customer based on market research and real data about existing customers. It helps marketers and businesses tailor their strategies to better target and engage their audience.

Call to Action (CTA)

A prompt in the email that tells the reader what action they should take next, typically in the form of a clickable button or link.


Stands for Controlling the Assault of Non-Solicited Pornography and Marketing Act, a law that sets the rules for commercial email and gives recipients the right to stop receiving emails.


Stands for Canadian Anti-Spam Legislation, which is Canada’s equivalent to the CAN-SPAM Act in the United States.

Click-Through Rate (CTR)

The percentage of your audience that advances (or clicks through) from one part of your website to the next step of your marketing campaign.

Cold Email

An unsolicited email sent to a potential client, lead, or prospect without prior contact or relationship. It's typically used for outreach, sales, or networking purposes.

Contact List

A collection of email addresses used in email marketing to distribute content, offers, and promotions.

Conversion Rate

The percentage of email recipients who complete a desired action after clicking on a link in an email, such as making a purchase.

CPM (Cost Per Thousand)

The cost an advertiser pays for one thousand views or impressions of an advertisement.

Customer Acquisition Cost (CAC)

The total cost associated with acquiring a new customer, including all marketing and sales expenses.


The ability of an email to reach an inbox without being blocked or rerouted by spam filters.

DKIM (DomainKeys Identified Mail)

An email authentication method designed to detect email spoofing by providing a mechanism for validating a domain name identity associated with a message through cryptographic authentication.

Double Opt-In

A two-step process where a person who signs up to receive emails must confirm their email address by clicking a link in a confirmation email.

Drip Campaign

A method used in direct marketing where a set of predetermined emails are sent out automatically on a schedule.

Email Automation

The process of sending time or action triggered emails to subscribers with relevant information.

Email Body

The main content of an email message, excluding the subject line, header, and footer. It contains the primary message, graphics, links, and other relevant details the sender wishes to communicate to the recipient.

Email Campaign

A coordinated set of email marketing messages delivered at intervals and designed to achieve a specific goal.

Email Service Provider (ESP)

A company that offers email marketing or bulk email services.


The bottom section of an email that usually contains sender information, such as company name, contact info, and unsubscribe links.

Hard Bounce

Email that has been returned to the sender due to a permanent reason, like a non-existent address.

HTML Email

Emails that include graphics and colors and look similar to a webpage. They provide a more visually engaging experience than plain text emails.

Inbox Placement

Where your email ends up once it’s delivered - in the inbox, spam folder, or another location like Gmail’s Promotions tab.

IP Address

A unique set of numbers and/or letters that identifies a sender's location on the internet.

IP Warming

The practice of gradually increasing the volume of mail sent via a dedicated IP address according to a predetermined schedule. This helps build a positive sending reputation with Internet Service Providers (ISPs) and reduces the likelihood of being flagged as spam.

Key Performance Indicator (KPI)

A measurable value that indicates how effectively a company or individual is achieving specific business objectives.

Landing Page

A standalone web page designed to capture leads.

Lead Nurturing

The process of developing and reinforcing relationships with potential customers at every stage of the sales funnel through targeted and relevant content.

List Hygiene

The practice of maintaining a clean email list by removing inactive or unengaged subscribers.

List Segmentation

The process of dividing an email list into more targeted groups for personalized marketing.

Mobile Optimization

Designing emails to ensure they are readable and easily navigable on mobile devices.


A regular communication, usually in the form of an email, sent to a list of subscribers that provides updates, news, or content related to a specific topic or organization.

No-reply Address

An email address set up by organizations to send messages without allowing recipients to reply directly to that specific address.

Open Rate

The percentage of email recipients who open a given email.

Opt-In (or Subscribe)

To give permission to receive email communications by actively checking, ticking, or filling a form.

Opt-Out (or Unsubscribe)

When a user chooses not to receive email communications.

Permission Marketing

Marketing centered around obtaining customer consent to receive information from a company.


The practice of creating personal, relevant messages to individual subscribers using data like their name, location, or behavior.


A fraudulent attempt, usually via email, to steal personal information or credentials by masquerading as a trustworthy entity. 

Plain Text Email

An email composed solely of text without any formatting, images, or graphics. Unlike HTML emails, it appears the same regardless of the recipient's email client or platform, ensuring compatibility and deliverability.

Preview Text (or Pre-header text)

A short summary text that follows the subject line when an email is viewed in the inbox.

Promotional Email

A type of email specifically designed to introduce offers, discounts, or new products to recipients, with the goal of driving sales or engagement. They are often sent to subscribers or customers as part of a targeted marketing campaign.


The individual or company to whom an email is addressed and intended to be delivered to.

Reply-to Address

An email address specified by the sender where responses to the email should be directed. While the "From" address indicates the sender, the "Reply-To" address ensures that any replies from the recipient go to a designated inbox, which may differ from the original sending address.

Responsive Design

Email design technique that ensures emails are readable and navigable on any device, whether it be desktop, tablet, or mobile.


Online advertising strategy that targets users who have already visited your website or engaged with your email content.

Sender Name

The displayed name in an email that identifies who or what organization the email is from, often used to provide recipients a recognizable point of reference.

Sender Reputation

A score assigned by Internet Service Providers (ISPs) that can affect your email deliverability.

Single Opt-In

A one-step process where a person who signs up to receive emails is immediately added to the email list.

Soft Bounce

Email that is returned to the sender due to a temporary issue, like a full inbox or an offline email server.

Spam (or Junk)

Unsolicited, irrelevant email, sent in bulk to a list of people.

Split Testing (or A/B Testing)

A method to test two versions of an email to see which one performs better. It is a way to test changes in elements like subject lines, images, content, calls to action, etc.

Subject Line

The title of your email, which recipients see in their inbox.

Transactional Emails

Emails that are triggered by a user's interaction with a web app or website, like a purchase receipt or password reset email.


A list of individuals or entities waiting for a specific product or service. Waitlists are often used when availability is limited.

Welcome Email

The first email subscribers receive once they join your email list, often thanking them for subscribing and setting expectations for future emails.


A list of accepted email addresses that an ISP, a subscriber, or other email service provider allows to deliver emails directly to the recipient's inbox.

Put your email marketing knowledge to work with Loops

Email marketing remains one of the most powerful tools in an email marketer's playbook. But, like any tool, its success is defined by how well we understand the fundamentals. 

If you’re just getting started in email marketing, these terms will be a great starting point. If you’d consider yourself an expert in the field, these terms will be worth taking a deep dive into. 

As you begin drafting your next email campaign, lean on this glossary as a helpful reminder of all the nuances in email marketing. 

At Loops, we have taken all of these nuances into consideration and have built a modern way to send marketing and transactional emails. If you’re ready to put your knowledge to work, give us a try for free. 

Ready to send better email?

Loops is a better way to send product, marketing, and transactional email for your SaaS company.

Ready to send better email?

Ready to send better email?

Loops is a better way to send product, marketing, and transactional email for your SaaS company.

Loops is a better way to send product, marketing, and transactional email for your SaaS company.