Knowledge is power. So let's demystify all the jargon you'll come across on your path to becoming a great email marketer.

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A/B testing

A/B testing trials the effectiveness of digital marketing assets, such as landing pages, display ads, email newsletters, and social media posts. Two versions of an asset are created to see which ones resonate with users more. In a typical A/B test, half of the user group receives “version A,” while the others get “version B.” Metrics that A/B tests typically measure are conversion rates such as purchases, links clicked, or forms completed.

Buyer personas

Also known as a “customer avatars,” a buyer persona is a fictional profile that marketers create to represent their company’s ideal customer.The profile can include demographic and also psychometric data. Buyer personas are essential to marketing messaging creation and product development.

Click-to-open rate

Click-to-open-rate (CTOR) is the number of unique clicks as a percentage of unique clicks within an email. This metric shows exactly how successful the email was, as it determines the level of interest and engagement from the subscriber once they open and read the email.


DKIM stands for DomainKeys Identified Mail. It’s another email authentication protocol that lets companies verify that messages were sent from authorized servers by using “public key cryptography.” It also protects against forgery and spam.


DMARC stands for Domain-based Message Authentication, Reporting, and Conformance. It’s a technical standard that is in place to protect both senders and recipients from spam, spoofing, and phishing. How it works is it checks whether email authentication is being used, by matching the domain in the email “from address” to the sender domain.

Double Opt In

Double opt-in (DOI), is a subscription process that requires two steps. After a user opts in to receive messages by providing their contact details, they’re instructed to look out for a confirmation message – usually through an email. While it is less streamlined than single opt-in, it also guarantees that the user has explicitly given their consent.

Dynamic Content

Dynamic content is web-based content that changes based on user data, preferences, and behaviors. This data is largely supplied by the user, who provides and then consents to its use. With dynamic content, you can customize every aspect of an email to target a particular user. Everything from a user’s interests, gender, purchase history, and even geography can be used to personalize an email.

Email Deliverability

Email deliverability is when an email successfully arrives into a recipient’s inbox. Which is not to be confused with email delivery, which simply means that an email has been successfully delivered to the recipient’s server. There are a number of factors that affect email deliverability, such as audience engagement, spam complaints, sender reputation.

Hard Bounce

A hard bounce is when an email was completely undeliverable, and delivery should not be attempted again in the future. Hard bounces happen because: the email address or recipient doesn’t exist, the email domain doesn’t exist, the recipient’s server has blocked delivery, or the email address is invalid.

MX Records

MX Records stands for “mail exchange” records. They are used to communicate which mail servers can accept incoming mail on behalf of a domain, and also where the emails should be routed to. If your MX records aren’t configured to the right location, you won’t receive any emails. As this is an important part of validating your sender domain, the emails you send may also be rejected.


The Net Promoter Score (NPS) is an index that ranges from -100 to 100. It is a way to measure how willing customers are to recommend products or services to other people, and ultimately gauges customer loyalty. NPS scores are determined through single question customer surveys and customers are put into one of three categories: detractors, passives, and promotors.


Segmentation is an email marketing strategy that separates subscribers into subgroups to deliver custom messaging. Subgroups are created based on demographics, such as location, gender, age, ethnicity, etc., but can also be based on customer behavior such as past purchases. Other subgroups can be based on psychographic data, which is related to subscribers’ values and beliefs.

Sender Reputation

Sender reputation, a score that an Internet Service Provider (ISP) assigns to any company that sends out emails, is integral to improving deliverability. It’s fairly straightforward – the higher your score, the more likely your email will land in your customer’s inbox. Maintaining sender reputation is important, as if scores fall below a certain level, ISPs will either reject emails or send them to spam folders.

Single Opt-In

Single opt-in (SOI) is when a user opts in by providing their contact details via a sign up form. This implies that they have given consent to receive messages from you. It’s what it sounds like – an opt-in method for new subscribers that only requires a single action such as a checked box.

Soft Bounce

A soft bounce occurs when an email fails to deliver but the email address is still considered valid, which indicates a temporary issue with the mailbox. Your email provider will usually attempt delivery to an address over a few days before marking it as a soft bounce. And this happens for a number of reasons: the recipient’s inbox or server is full, the target server is down, or your email is too large to be delivered.

Spam Traps

Spam traps are email addresses maintained by ISPs that do not open or engage with emails. There are two types of spam traps – the first type are honey pot emails, which are created and added into websites and forums in plain sight to lure in spammers. The second type, recycled email address, used to belong to someone but have since been abandoned or closed down. They’re then reactivated later on to monitor any spammers still sending to that address.


SPF stands for Sender Policy Framework. It’s an email authentication technique that works by detecting forgery and spam. It works similarly to DMARC, which shows the subscribers’ servers that they’re a legitimate sender. In simple terms, it allows email clients to check that the mail server sending your email is on your verified list.


Webhooks are one of the few ways web applications can communicate with each other. It allows you to send real-time data from one application to another automatically, whenever a given event occurs. They’re considered less resource intensive than APIs, as it saves time from constantly polling (checking) for new data.


Whitelisting adds an email or IP address to your list of verified contacts, which communicates to inbox filters that this address is a trusted source. It’s possible to ask subscribers to whitelist you, which will help to improve email deliverability. An ideal way to get whitelisted is to link to a set of instructions in your email campaign. Remember, a request to be whitelisted is a tall order, so make sure you’re reserving it only for your most loyal of subscribers.