Just like with anything tech-related, the deeper you dive into the specifics of email marketing the more you’ll come across insider lingo that will have you reaching for your dictionary. Unfortunately, not even Merriam Webster can tell you what SMTP means. We thought we might lend a hand and fill that role, however. Please find this handy reference alphabet of email marketing terms that will finally clear up what some of the more cryptic terms and acronyms associated with email marketing really mean. We’re still working on putting it to the tune of the alphabet song but nothing really rhymes with “multivariate”.

A/B testing

  • Also known as “split testing”, A/B testing is the process of testing which email design, content, subject line, send time, or any other aspect of a given email is most effective by sending both the “A” and “B” emails to similar audiences and comparing their results.

Bullet-proof buttons

  • Not quite an image, not quite text, the bullet proof button is best of both worlds when it comes to designing an email. Bullet proof buttons utilize the “cell” feature in html that give them the appearance of an image, all without ever having to gain permission from the email provider to display.


  • Call To Action. Your CTA is the central message of your email that lets the reader know exactly what you want them to do, preferably in a visually appealing and engaging way.

Dynamic content

  • HTML code that allows your email to adapt and appear unique to different users.
    • Ex: Utilizing a “merge” tag allowing your reader’s first name to appear in the subject line of an email, giving the appearance that it is a personalized message.

Engagement scoring

  • A tool that utilizes tags and weighting to grade your current and potential clients by their level of interest, what products they are interested in, and the types of email content they engage with.


  • FeedBack Loop. A service often offered that lets you know when your clients send your emails to the spam or junk folder.


  • Determining the physical location of your email recipients based on their IP address to improve your strategic targeting in future campaigns.

HTML Emails

  • HyperText Markup Language is the coding language used to add more advanced structure and flair to your emails, as opposed to plain text emails which are, as the name implies, simply text.


  • Internet Message Access Protocol. A standard email protocol that stores emails remotely on a mail server but allows users to access each email as if it was stored locally. For instance, this allows you to access your Outlook emails from your desktop program as well as your smartphone app.


  • Joint Photographic Experts Group. A type of image file named after its creator which requires permission to be viewed when sent in an email.


  • Key Performance Indicator. Benchmark statistics by which one judges the success of a given project. For email marketing the most common KPIs are open and click rates.

List fatigue

  • The decrease in responses from a given email list over time, typically as a result of loss of interest from certain recipients, changed emails yet to be scrubbed or fixed, or inaccurate email addresses. List fatigue is one of the primary drains on the reporting of a given email campaign.

Multivariate testing

  • Similar to A/B testing, multivariate testing is also a process of determining which email is most effective, the only difference being the amount of variables tested.
    • Ex. When designing an email, you can’t decide on either the headline or the accompanying image to be used. If you were to perform a multivariate test, you would test every possible combination of those variables to determine which mix performs best.

Nth name

  • A random sampling technique used to split test an email by pulling every nth names from the list of emails using their given cell numbers.

Open rate

  • The total number of emails sent divided by the amount of emails opened, multiplied by a factor of 100. The open rate represents the percentage of recipients who opened your email.

Plain text email

  • Plain text emails are the opposite of HTML emails in that they are built with no code formatting, instead they simply consist of text. It is common practice to include both an HTML version as well as a plain text version of an email in your campaign as it helps to manuever around spam filters. The plain text version can also be read on devices with less capability than a computer or smart phone, like the Apple iWatch for instance.

Quality assurance

  • The process of confirming the content of your email is flawless before launch. This process includes checking, rechecking, and cross checking emails and a litany of testing across all platforms and devices your recipients may use.

Responsive email design

  • The ability of an email to adjust across platforms (desktop, mobile, tablet, etc.) and browsers (Internet Explorer, Chrome, Firefox, etc.) while maintaining its full aesthetic appeal and functionality.


  • Simple Mail Transfer Protocol. Refers to the web protocol in place to communicate between the program sending and the program receiving an email.


  • The process of refining your audience and focusing your email’s message to appeal specifically to said audience.

Uniques (clicks, opens)

  • The number of clicks, opens, or any other success metrics set on an email campaign that come from unique IP addresses. This number is a more accurate measure of the success of your campaign since otherwise a single person opening the email over and over can skew all of your results.


  • A program that verifies the sender of the email is who they say they are. If the sender cannot be verified the email is sent to the junk folder.


  • A tool used in engagement scoring to assign a “weighting number” to a given success metric in order to prioritize the scoring of that metric over other, less important metrics.
    • Ex: an email announcing the launch of a new fund might have a link to a fund brochure and to the company homepage. In this instance, you can assign a larger weighting to a click on the fund brochure since it is more relevant to the success of the campaign.

(X) Cross-campaign profiling

  • The practice of monitoring a client’s behavior across multiple campaigns in order to get a better understanding of their preferences so you can target them more accurately in the future.

Year-over-year profiling

  • Just one of the many filters by which you can compare post-campaign data that provides useful knowledge of your email performance progress from a macro point-of-view.

Zip file

  • A file format that supports lossless data compression. It is a useful tool when attaching files to emails that would otherwise be too large to send.