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Your A-Z Guide of Essential Email Marketing Terms

Struggling to differentiate alt-text from above the fold? Or just want a refresher course on some essential email marketing terms? We’ve got you.

Whether you’re an experienced email marketer or a newbie to this complex world, there’s always more to learn. As an industry, email marketing is constantly evolving to meet customer expectations and needs.

Make sure you’re not left behind, check out our list of essential email marketing terms below.

Above the fold: The top section of an email—your readers can see it without any scrolling needed! Originally coined in newsrooms, you should be putting your most important message in this section.

A/B testing: This is everything to an email marketer—test, test, and test again. If you’re sending an email to your customers, segment (see segmentation below) your list and test the email with different subject lines, images, headings, copy, or creative. This is a good way to see what your customers respond to so your emails convert!

Alt-text: Alt-text (also known as the alt tag) is a word or phrase that’s inserted in your email’s code as an attribute of an image to let search engines know the contents of the image. If something goes wrong in your email and an image doesn’t load (just saying, that wouldn’t happen with stensul), this is also the text that appears in the image box.

API: This stands for Application Program Interface and it’s how one program accesses another program to transfer data. For example, stensul uses an API to send your perfectly designed and coded emails to your ESP.

Bounce rate: This is the number of hard or soft bounces your email gets upon delivery, divided by the number of people you sent it to. A hard bounce is when you send an email to an invalid, closed, or nonexistent email account. A soft bounce is when you send an email to a live address but it’s turned away before it gets delivered. This is often due to a temporary problem like their server is down or the recipient’s mailbox is over quota.

Brand compliant: An email that conforms to your brand and company guidelines. As in, you’re using the right colors, logos, and fonts—all that good stuff!

CASL: The Canadian Anti-Spam Law, or CASL, is known for being one of the toughest laws of its kind. It’s main requirement is that Canadian or global companies that send emails within Canada must receive consent from all recipients before sending emails.

CAN-SPAM: The CAN-SPAM Act is a U.S. law that dictates the rules for commercial emails, allows recipients the right to opt out of emails, and provides strict punishments for violators.

Conversion rate: Ready to measure the success of your email campaign? This rate gives you a metric for the effectiveness of your campaign. For example, the number of people who clicked on a link in your email and bought your product.

CTA: The call to action is the plug or “sell” in your email that lets your recipients know what you want them to do, whether it’s schedule a demo, buy a product, or read an eBook.

CTR: The click-through rate is the percentage of people who clicked on a link within your email divided by the number of people who opened it.

Deliverability: This refers to the likelihood that your email will be successfully delivered to your intended recipients, rather than mistakenly blocked by ISPs and spam filters.

Design compliant: Similar to brand compliant, this email will follow your brand’s specific design guidelines around colors, images, graphics, and other visual elements. Don’t cross the designers!

Double opt-in: Double opt-in is the recommended process for subscribing email recipients to your email list. How does it work? Well, once a recipient has signed up to receive news or product updates from you, they’ll get a confirmation email asking them to verify that they want to receive emails from your brand.

Dynamic content: This is a section within your email that changes its content based on the user receiving the email. This is usually determined by preferences or data that a user has already provided to you, like past purchases, location, interests, etc.

ESP: This stands for Email Service Provider, a company that offers email marketing automation and bulk email services. Stensul is ESP agnostic, which means we can build perfectly coded and designed emails for any ESP on the market.

Footer: The section at the bottom of your email, usually contains all the fun (but very necessary) legal information like your company name, address, contact info, and unsubscribe or opt-out links.

Legal compliance: This means your email conforms to a diverse range of legal regulations (like having all the above footer info!).

Mobile optimized: Congratulations,your email was built for mobile devices, which is important considering a whopping 46% of all email opens are on mobile.

Mobile responsive: You’re one of the lucky ones, mobile responsive emails are the bees knees of the email marketing world, cleverly adapting their design and layout depending on the device that’s viewing them. Check out stensul’s Grubhub case study to see how important mobile responsive emails are!

Nurturing: The process of sending a scheduled series of emails to a potential customer to spark their interest, create engagement, move them through the buying stages, and lead them to an action.

Open rate: In addition to the click-through rate, this is one of the key metrics of an email campaign’s success. The open rate is the percentage of people who opened your email.

Opt-out: This approach to email lists may not be recommended, as it involves brands adding recipients to email lists until they specifically ask to be unsubscribed. In some cases, this may be illegal.

Plaintext version: Let’s get a little techy for a second. A plaintext version of an email is a non-HTML version that’s only shown to people who opened the email on a device that doesn’t support HTML.

Pre-text: This is the text that sits above the header and is viewable in a mobile device’s inbox.

Seed list: These are email addresses that are placed on a list to gauge what emails are being sent to that list, track the deliverability rate, or see how emails appear in an inbox. For internal emails, you may put a senior executive on a seed list so they can track your email output.

Segmentation: Want to get more targeted with your email sends? Segmenting your list is a great way to send more customized messages. To do this, divide your email list into various sub-groups, determined by a range of attributes, like demographic, age, location, purchase history, or open history.

Subject line: This is the copy you see next to a sender’s name in your inbox. It gives you a little taste of what the email is about. For email marketers, the subject line is essential, as it needs to entice recipients to open the email.

Suppression list: Legally required by CAN-SPAM, this list includes any recipients who have opted out of your emails or notified other mailers that they don’t want to receive mailings from your company.

Tags: These clever tags (also known as tokens), such as [FIRSTNAME], allow you to personalize your emails in bulk email sends. This means you’re starting your beautifully designed emails with a nice “Hi Alex” or “Hi Hayley,” instead of the generic “Hello” or “Hi there.”

Transactional emails: These are emails that are sent after a specific action, like confirmation emails or receipts.

Triggered emails: The beauty of automation! Triggered emails are pre-programmed to send automatically on certain dates, like birthdays or anniversaries.

WYSIWYG: “What you see is what you get” email editors (also used in website editors) allow the user to edit an email visually, rather than editing the code directly.

That’s just a few of the essential email marketing terms you’ve probably already stumbled across. If you think we’ve missed any, or just want to chat about the cool world of email marketing, get in touch at

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