Emails allow you to communicate directly with your customers and curious email subscribers. According to a 2023 Litmus survey, 87% of marketing leaders consider email essential for success. Developing a strong email marketing strategy can help you build better consumer relationships and encourage users to make purchases, sign up for newsletters, or download your apps.
If you’re new to this practice, learning basic email marketing terms is the first step to understanding why some campaigns land in inboxes while others vanish into spam folders, and why certain messages drive sales while others get ignored. Here are 25 must-know email marketing terms and the role each one plays in growing an online business.
25 email marketing terms
- A/B testing
- Acceptable spam report rate
- Acceptance rate
- Application programming interface (API)
- Blast
- Blacklist
- Bounce rate
- Call to action (CTA)
- CAN-SPAM Act
- Churn rate
- Click-through rate (CTR)
- Click-to-open rate
- Conversion rate
- DomainKeys Identified Mail (DKIM)
- Email service provider (ESP)
- General Data Protection Regulation
- Hard bounce
- Internet protocol (IP) address
- Opt-out
- Sender Policy Framework
- Sender reputation
- Single and double opt-in
- Soft bounce
- Spam folder
- Targeted emails
Here’s what each email marketing term means and how it affects your campaigns:
1. A/B testing
A/B testing, or A/B split testing, compares two versions of the same asset to see which one performs better based on user behavior. In the context of email marketing, you can A/B test subject lines, images, content formats, or promotional offers to see which versions are most effective at boosting metrics like open rate, click-through rate (CTR), and conversion rate. Most email marketing software platforms can automatically distribute the email with the winning subject line or other creative element.
2. Acceptable spam report rate
Spam report rate refers to the percentage of users who mark content as spam. When too many customers do this, it can hurt your email sender reputation. An acceptable spam report rate is typically less than 0.1%. Anything higher signals it’s time to revisit your content or sending frequency.
3. Acceptance rate
Your acceptance rate, or email deliverability rate, is the percentage of sent emails that arrive as planned in your recipients’ inboxes. Successful delivery doesn’t guarantee the consumer opens your message, but the acceptance rate verifies your email wasn’t blocked or rejected. Poor sender reputation, high-volume sending, and a domain name that doesn’t conform to the Domain Name System (DNS) can cause mail servers to flag your message as spam. An acceptance rate of 95% or higher indicates your email marketing program is in good working order.
4. Application programming interface (API)
APIs let your applications or software tools talk to each other automatically. In the context of email marketing, those tools are usually your customer relationship management (CRM) platform and email service provider. Email marketing teams use API protocols to automate emails in response to specific consumer actions, like sending a confirmation email after a purchase. This automation saves hours of manual work while ensuring customers hear from you at the right moments.
5. Blast
An email blast is a large-scale delivery, designed to reach as many consumers as possible. Blasting your email list involves sending a single message to your audience, either your entire subscriber base or a large portion, without segmenting recipients or tailoring content. It’s often used for major announcements, such as product launches or promotions.
6. Blacklist
Blacklists are records of suspicious domain names and IP addresses that have been flagged by email providers, internet service providers, and third-party security companies. These lists are designed to identify spam accounts and reduce unsolicited emails. Quality issues or aggressive tactics can get your business placed on a blacklist, decreasing your email deliverability rate and making it difficult to reach your audience.
7. Bounce rate
Bounce rate measures the percentage of sent emails that could not be delivered to recipients’ inboxes. Email bounces occur when there are invalid email addresses or full inboxes. This figure does not include blocked emails, which are rejected due to quality issues.
8. Call to action (CTA)
A call to action (CTA) is the text prompt, hyperlink, or button that encourages consumers to take the next step, like “Buy Now,” “Sign Up,” or “Learn More.” In email marketing, CTAs typically appear in the body of the email.
9. CAN-SPAM Act
The CAN-SPAM Act, or the Controlling the Assault of Non-Solicited Pornography and Marketing Act, regulates the distribution of commercial emails. It outlines requirements such as providing an option to opt out of receiving them, using accurate sending information and subject lines, and labeling advertising content. The Federal Trade Commission (FTC) enforces CAN-SPAM, and failure to comply may lead to fines.
10. Churn rate
The churn rate is the percentage of subscribers who leave an email list, often referred to as unsubscribing. This can happen both voluntarily or because of bounces or spam complaints, but a high percentage is a sign your recipients aren’t interested in your content.
11. Click-through rate (CTR)
Click-through rate (CTR) is an email marketing metric that measures the percentage of users who engage with your email messages by clicking on a link. Email links often drive customers to product pages, dedicated landing pages, or other web pages.
12. Click-to-open rate
Click-to-open rate measures the percentage of email recipients who open a message and then click a link inside it. A higher percentage means your content is compelling enough to drive action—not just opens.
13. Conversion rate
A conversion rate measures the percentage of users who complete a desired action after engaging with your marketing or advertising content. Your email campaign goals determine what conversion means for you. It could be a form submission, purchase, content download, or other consumer action.
14. DomainKeys Identified Mail (DKIM)
DomainKeys Identified Mail is an email authentication protocol that helps verify your emails are legitimate. Servers use DKIM encryption keys or digital signatures to verify that the content originated from a legitimate email sender and hasn’t been modified. Proper DKIM setup can improve deliverability and help keep your emails out of spam folders.
15. Email service provider (ESP)
An email service provider is a platform for sending and receiving emails. Gmail, Outlook, and Proton Mail are common ESPs. An ESP allows brands to run email campaigns at scale.
16. General Data Protection Regulation (GDPR)
The GDPR is a European data and privacy law that regulates the handling and processing of personal information, including individual email addresses. This legislation applies to any company that collects data from European Union (EU) citizens, even if the business operates in the US. The EU enforces these protocols, and violators may be subject to fines.
17. Hard bounce
A hard bounce is an email delivery failure that cannot be reversed. These are often the result of issues like invalid email addresses or inactive domains and negatively affect bounce rates. Hard bounces negatively affect bounce rates and signal you should clean your email list.
18. Internet protocol (IP) address
Every internet-connected device has an IP address, which is a unique numerical identification code. They are significant in email marketing because mail servers use IP addresses to identify email origins, and your sender reputation is tied to your address.
IP addresses can be shared or dedicated. With a shared IP address, multiple devices can send communications from the same IP. With a dedicated IP address, your identifying code is associated with a specific device. For newer stores with smaller lists, shared IPs work fine. As you scale up in subscribers, a dedicated IP gives you more control over your deliverability.
19. Opt-out
An email opt-out means the recipient actively chooses to unsubscribe from marketing or promotional materials. According to CAN-SPAM regulations, emails must include a clear way for recipients to opt out permanently from unwanted messages.
20. Sender Policy Framework
Sender Policy Framework (SPF) is an email authentication process designed to help prevent phishing attacks and email impersonation. This protocol allows a brand, as a domain owner, to create and publish an SPF record in its DNS—essentially an approved sender list.
The SPF record names the mail servers and IP addresses authorized to send emails on behalf of the brand’s domain. Receiving mail servers can check the domain’s SPF record to verify that the originating IP address is authorized to distribute content from that domain; if the IP address isn’t on the approved sender list, the message may be flagged as spam.
21. Sender reputation
Sender reputation is an assessment of the quality and trustworthiness of the messages your company sends. Email service providers calculate sender scores and take actions based on the results. Quality issues and spam complaints may result in a lower sender score, leading to blocked emails and fewer messages reaching your customers.
22. Single and double opt-in
Use single or double opt-in processes to obtain consumer consent to receive marketing emails. Single opt-in sign-ups are quick: users provide an email address, typically by submitting an online form, and are added to a subscriber list. Double opt-in is a two-step process, and it often involves submitting a web form and then clicking an email link to confirm subscription. A double opt-in protocol helps you avoid low-quality leads and reduce bounce rates by weeding out fake email addresses.
23. Soft bounce
Soft bounces are temporary email delivery failures, often caused by a full mailbox or a temporary service outage. Like hard bounces, they can negatively impact email deliverability and hurt your overall sender score. However, unlike hard bounces, soft bounces are retried, meaning they may eventually reach their destination, albeit with a delay.
24. Spam folder
A spam folder is a dedicated email inbox for unwanted emails. Email service providers use spam filters to sort suspicious content into these folders, and recipients are not notified when they’re received. To stay out of spam folders, authenticate your domain with SPF and DKIM, remove inactive subscribers quarterly, and keep complaint rates below 0.1%.
25. Targeted emails
Targeted emails are customized messages designed to appeal to a specific audience segment, such as by demographics or geographical area. Successful email targeting can lead to an increased conversion rate, directly boosting your bottom line.
Email marketing terms FAQ
What are the five Ts of email marketing?
The five Ts of email marketing are tease, target, teach, test, and track. Tease refers to your subject line grabbing attention. Target means sending to the right audience segments. Teach provides value in your content. Test involves A/B testing elements to improve performance. Track means measuring results and adjusting your approach based on what the data shows. This framework describes the essential elements of an email marketing campaign.
What is the rule of seven in email marketing?
The rule of seven is a broad marketing theory suggesting it takes seven brand interactions to convince consumers to convert. This principle does not exclusively refer to email marketing strategy, although email communication is a valuable touchpoint that can contribute to conversion.
What are the four Ps of email marketing?
The four Ps are product, price, place, and promotion. According to this theory, effective marketing materials should address each of these key elements. For email marketing, this means highlighting what you’re selling, why the price offers value, where customers can buy, and what promotion or offer makes now the right time to act.
