Making sense of email marketing terms can sometimes feel like you’re trying to learn a new language, and it’s normal to feel lost. But intense as the jargon is, it’s important to have a clear understanding of the basics. Some terms have legal implications that are crucial to be aware of, while others represent trends and practices that you’ll want to work into your strategy.

So, instead of smiling and nodding along in those marketing meetings, get to know some of the most-used terms. To help you get up to speed, we’ve put together this quick glossary of 20 email marketing terms that you need to know, along with some of our resources that will give you more in-depth knowledge. Let’s get to it.

1. Acceptance Rate

This is the percentage of emails you send out that are accepted by your recipients’ email servers and is sometimes referred to as the deliverability rate. It doesn’t necessarily mean that an email made it into an inbox, just that it didn’t bounce back.

2. Bounce Rate

Speaking of bounces, the bounce rate refers to the percentage of emails you send out that are not accepted by your recipients’ email servers.

3. Bulk Emails

Marketing or advertising emails sent out to large groups of people at once. These are generally canned text emails, meaning they are not personalized to each recipient — though they may still be targeted to a specific segment of your audience.


The Controlling the Assault of Non-Solicited Pornography and Marketing Act of 2003, which dictates guidelines that businesses must follow when sending commercial emails. Under CAN-SPAM (which is enforced by the FTC, or Federal Trade Commission), recipients must have a visible and operable way to unsubscribe from your messages, and your emails must contact accurate “from” lines, among other provisions.

5. CTR (Click Through Rate)

This is the percentage of recipients that click on a link in your email and is calculated by dividing the number of unique clicks on a link by the number of emails that were opened. The higher your CTR, the better.

6. Conversion Rate

The number of people who follow through on your email’s call to action. This can be a click, a download, a purchase, or some other action, and is one of the top indicators of your email’s performance.

7. Double Opt-In

A double opt-in is when you require that a subscriber goes through a two-step process to subscribe to your email — usually a standard sign up followed by a confirmation email with a link.

8. Email Campaign

An email or series of emails driven toward a unique marketing goal.

9. Hard Bounce

This is a type of bounced email where delivery fails due to a fixed reason, such as a blocked or invalid email address.

10. HTML

A type of email that allows you to customize your design and format more so than you can with a standard plain text email.

11. IP Warming

Sending emails to a recipient at a gradually increasing volume to establish the relevancy of your IP address.

12. List Segmentation

Separating your contact list into distinct groups (usually those in the same phase of the funnel) for the purpose of sending more targeted and relevant content.

13. Open Rate

This is the percentage of emails you sent out that were opened by their recipients.

14. Opt-In

To subscribe to an email. It’s important that your leads opt-in since this means they are interested in hearing from you and thus more likely to engage. Sending emails to individuals who haven’t opted-in can also be detrimental to your IP.

15. Opt-Out

To unsubscribe to an email. It’s required that you provide a clear way for recipients to opt-out from your emails and that you honor removal requests when they occur.

16. Personalization

Features within an email that are customized for their recipient. This can include using their name, inputting product recommendations based on their preferences, and sending unique content based on where they are in the buyer’s journey.

17. Sender Score

The reputation of your IP address scored from 0 to 100. Think of it like a credit score, where the higher your score, the more reputable your IP. Email services use this score to help determine who gets sent to the inbox and who doesn’t.

18. Single Opt-In

A one-step opt-in process to receive your emails. Unlike double-opts, this could lead to less engaged recipients since they haven’t confirmed their interest.

19. Soft Bounce

When emails were accepted by the server but still sent back to you undelivered. This can happen for a few different reasons, including full mailboxes and emails being too large.

20. Spam

Also referred to as junk email, these are messages that are unsolicited and unwanted, and thus filtered out of the inbox. Your emails can be classified as spam if they’re sent to recipients who didn’t opt-in to hearing from you. And in addition to missing the inbox, sending spam can harm your IP and hurt your acceptance rate. There can also be legal consequences.

We hope you found this crash course in email marketing terms helpful! Let us know if there’s anything we’re missing that you’d like to know more about.