120 Email Marketing Terms Every Marketer Should Know


Table of Contents

We marketers sure do like to use our marketing lingo. Without a little help, it can almost sound like we're speaking another language sometimes. But have no fear – this list of 120 email marketing terms is the most comprehensive resource we know of for an email marketing glossary. Whether you're an email pro or an email newbie, if you come across a term you aren't sure of, chances are it's listed here.

  1. 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.
  2. Acceptance Rate: The percentage of email messages that a mail server accepts. 
  3. ALT tags: Part of the code that creates an image. ALT tags contain text that describes the image.
  4. Animated Gif: An image that changes, like animation but with only a couple of frames. Animated gifs can be used in emails.
  5. Attachment: 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.
  6. Authentication: 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.
  7. Autoresponder: An automated message or series of messages. Sometimes called a “drip campaign”.
  8. Behavioral Email: A way to customize which email messages a subscriber get based on how they have behaved in the past.
  9. Blacklist: 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.
  10. Block: A severe email deliverability problem. A block is when none of a sender’s email messages get through.
  11. 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.
  12. Broadcast: Similar to an “email blast”. When you send out the same email message to everyone on your list all at once.
  13. Bulk Folder: The polite term for the spam folder.
  14. 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.
  15. CAN SPAM: The 2003 American law designed to reduce spam from commercial emails.
  16. CASL (Canadian Anti-Spam Law): The Canadian equivalent of CAN SPAM law. CASL went into effect in June 2014.
  17. Cinemagraph: A very short looping movie that can be embedded into emails and on websites.
  18. 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.
  19. 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.
  20. Complaint Rate: A percentage of how many subscribers marked an email message as spam.
  21. Confidence Level: A testing term that’s represented as a percentage. Most marketers use a 95% confidence level, though some insist on the more rigorous (and trustworthy) 99% confidence level.
  22. Contact List: Another term for your subscriber list or “mailing list”.
  23. 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.
  24. CPM (Cost Per Thousand): An advertising or list management term that means “Cost per thousand”. Is sometimes interchanged with “CPT”.
  25. CSS: A markup language used to design emails and web pages. Stands for “Cascading Style Sheets”.
  26. Dedicated Server: An upgrade from a shared server. Refers to the computer server used to send email campaigns.
  27. Deliverability: The art and science of getting emails from a sender all the way to subscribers’ inboxes.

    email marketing terms deliverability

  28. Delivery Rate: What percentage of emails sent from the sender actually reach subscribers’ inboxes.
  29. Deploy: Another way to say “send”, as in “the email campaign was deployed”.
  30. DKIM (DomainKeys Identified Mail): An email authentician technique that links a domain name to an email message. Used to verify an email's authenticity and to increase deliverability rates.
  31. 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.
  32. Drip Marketing: Usually refers to automated marketing that sends a series of messages to prospects over time. Autoresponders are a type of drip marketing.
  33. Dynamic Content: A personalization technique that swaps different content into pre-defined parts of an email message based on a subscribers’ preferences, location or past behavior.
  34. Email Analytics: All the technologies and metrics used to measure email programs.
  35. 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.
  36. 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.
  37. Email Client: The software that a subscriber views their email messages in.
  38. Email Domain: The domain name, website or URL that an email is sent from. Typically, this is your company’s primary domain name.
  39. Email Harvesting: The spammer’s technique of stealing people email addresses by finding those addresses online and then adding them to a list without the email address owner’s permission.
  40. 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.
  41. 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.
  42. 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.
  43. Emoji: Special characters that create tiny images that you can embed in an email subject line, or anywhere else.
  44. Engagement: An umbrella term that covers every possible interaction an email subscriber can have with your message, like opens, clicks, shares and more.
  45. ESP (Email Service Provider): The company that provides software and hardware to manage your list and deploy and track your email messages.
  46. Forwards: A count of how many times one of your subscribers forwarded a message you sent them to someone else.
  47. Gif (Graphic Interchange Format): An image format commonly used online.
  48. 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.
  49. Gravestoning: An action taken by major ISPs like AOL, Gmail and Comcast where an inactive email is changed into a spam trap.
  50. 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.
  51. 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.
  52. Header: 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.
  53. 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.
  54. House List: Your core list of email subscribers.
  55. HTML5: A markups language that allows email coders and designers to do cool things like email carousels, video embeds, and more.
  56. 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.              
  57. Inactives: The subscribers on your list who have not opened or clicked in a month or more.
  58. Inbox Placement Rate: A percentage that expresses how often the emails you send actually reach subscribers’ inboxes.
  59. 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.
  60. 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.
  61. Jpeg (Joint Photographic Experts Group): A common file format of images.
  62. 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.
  63. 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.
  64. 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.
  65. List Fatigue: Declining engagement that occurs over time after an email list has been mailed to too frequently.
  66. 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.
  67. List Hygiene: How well your list’s information is kept up to date. This includes removing unsubscribes and inactives.
  68. 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.
  69. 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.
  70. 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.
  71. Onboarding: A marketing technique of educating new customers or clients in your business’s strengths and features. Welcome emails are common examples of onboarding.
  72. 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.
  73. Opt-in Rate: What percent of your website visitors (or landing page visitors) sign up for your email list.
  74. Opt-out: When people unsubscribe from your email list.
  75. Pre-Header Text: Part of an email message that is always text and appears right below the subject line when viewed in an inbox.
  76. Permission: The umbrella term for asking people to get your marketing materials, rather than just broadcasting your marketing at them.
  77. Personalization: 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.
  78. 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.
  79. Png (Portable Network Graphics): A file format commonly used online and in email messages.
  80. 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.
  81. Preview Pane: The top section of an email that is visible from the inbox dashboard view. Used less now than in years past.
  82. 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.
  83. Promotional Emails: As opposed to transactional emails. Emails sent out to announce or promote a product or service.
  84. 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.
  85. Re-engagement Campaign: An email campaign sent to try to get inactive subscribers to re-engage.
  86. Rendering: How an email message appears in each subscriber’s inbox.
  87. Re-send: The email marketing technique where you send the same email a second time to try to get more people to respond to it.
  88. Responsive Design: Design that will render properly on mobile devices, or any other device.

    email marketing terms

  89. Retention: A type of marketing that is focused on getting existing customers or clients to do more business with you, rather than finding new customers or clients.
  90. Revenue Per Email Sent: A metric that shows how much you’ve earned per each email you sent out.
  91. Scraping: 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.
  92. Segmentation: 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.
  93. 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.
  94. Sender Score: An email deliverability metric assigned by the company ReturnPath. A SenderScore of 70 is about average.
  95. Shared Server: As opposed to a dedicated server. The server your email messages are sent from.
  96. Signature File: A short default file at the end of email messages. Signature files usually include contact information.
  97. 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.
  98. SMTP (Simple Mail Transfer Protocol): The language or "protocol" servers use to talk to each other as they send emails around the world.
  99. 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.
  100. 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.
  101. Spam: 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.


  102. Spam Trap: An email address used by anti-spam entities to trap spammers.
  103. Spammer: Anyone who sends unwanted emails.
  104. 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.
  105. Subject Line: An email message’s equivalent of a headline, or title.
  106. Subscriber: The people who have signed up to receive your email messages.
  107. Subscriber Value: How much a subscriber is worth to you financially.
  108. 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.
  109. Targeting: Similar to segmenting an email list. A “targeted list” usually means a list of email subscribers who have very similar interests or behaviors.
  110. 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.
  111. Throttling: An email deployment technique. Throttling sends email messages out in batches, instead of all at once. This improves deliverability rates and server load management.
  112. 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.
  113. 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.
  114. UCE (unsolicited commercial email): A fancy term for spam.
  115. 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.
  116. 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.
  117. 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.
  118. Wearables: The next step after mobile devices. Wearables would include Apple’s iWatch, Google glass and other products.
  119. Welcome emails / welcome series: An email message or a series of email messages sent to new subscribers.
  120. White List: Email marketers often encourage subscribers to “white list” their emails. A subscriber white lists the email by marking it as important or moving it to an appropriate folder in their inbox.