All posts

Email Marketing Glossary

Email Marketing Glossary

Every word matters, especially in marketing. And while it is crucial for every professional to be familiar with the terminology from their field, we all have to start somewhere. Which is why we have compiled this email marketing glossary to help all the beginners out there.

Take a look at the list below to make your first steps into email marketing.

Click on the letter to skip forward.




Abuse emails – email addresses known for marking emails as spam.  

A/B split test – a test conducted to see which email variation works better. In brief, it can be explained this way: you’ve got one email and two subject lines; your recipients are divided into two groups, and they receive the same email but with different subject lines. By doing this you’ll see which subject line shows higher open rates, CTR, and results in better conversion.

Application Program Interface (API) – a kind of a mediator between a client and a server that helps the client to obtain certain information from it. Some email marketing software is available as API.

Attachment – any picture, GIF, video, etc attached to an email. Not recommended for promotions, as it is pretty suspicious to ESPs and can activate spam traps. We have written a detailed guide on email attachments.


B2B aka business-to-business, is a product or service exchange between businesses, as opposed to businesses and customers.

B2C – aka business-to-consumer. is a product or service exchange between a business and a customer directly.

Blacklist – a list of IPs, domains, and email addresses that are marked as distrusted and result in a high number of hard bounces. This is the first thing every email marketer should carefully avoid. You have a high chance of getting blacklisted if you don’t segment, personalize, or use purchased lists.

Block – a ban from your ISP to send emails to the recipients. You can be blocked by IP address or the domain that was reported to be sending spam.

Bounce rate – a percentage of emails that were not delivered to the recipients due to some problems. An acceptable bounce rate is up to 5%. The two types of bounces (hard and soft) are defined in the glossary further on.


CTA – aka Call-to-Action, is a word or a phrase used in an email to push the recipient to perform a certain action, such as click on a link, reply, make a purchase, etc.

CAN-SPAM – aka the Controlling the Assault of Non-Solicited Pornography And Marketing Act of 2003, is the US governmental document that regulates the sending of commercial emails and gives the recipients the right to stop receiving emails from you upon request. Non-compliance leads to tough penalties.

CASL – aka the Canadian Anti-Spam Law, is the Canadian equivalent of the CAN-SPAM law that went into effect in 2014.

Catch-all – an email address that will receive all messages sent to incorrect email addresses on a domain. While not a bad thing in itself, catch-all email addresses are avoided by most email marketers as they show extremely low open, click-through, and reply rates.

CTR – aka click-through rate, is the statistic that shows how many recipients have clicked on a link in your message.

Cold email – an email sent to a recipient without prior contact. An email equivalent of a cold call. It’s important to note that cold emails are not spam, but certain rules have to be followed.

Cold Email Sender – a tool that is used to create drip campaigns and send emails to recipients automatically, depending on the action performed by the recipient.

Complaint rate – a statistic showing the percentage of recipients who have marked your email as spam. A high complaint rate can lead to being blacklisted.

Conversion – turning a prospect into a customer/user. Refers to an action performed through your website or email: making a purchase by clicking a link, downloading content, signing up, etc.

Conversion rate – a percentage of recipients who turned from a prospect into a buyer/subscriber/user. This particular rate can be used to measure the success and efficiency of your marketing efforts.


Dedicated IP – an IP address that is only used by a single sender. If your IP address is shared (i.e. used by multiple senders), there is always a possibility that others might be sending unsolicited emails from the same IP address. Shared IPs are one of the reasons legitimate marketing emails get blocked.

Deliverability – a statistic showing how many emails actually got into your recipients’ inboxes.

Delivery rate – a statistic showing how many emails got to your recipients’ ISPs. A high delivery rate doesn’t necessarily mean high deliverability, as these emails still have to go through multiple filters.

Double opt-In – a preferable way of user confirmation to receive emails from you. Unlike single opt-in where a person fills in their email and any additional data to give their consent,  double opt-in requires an extra confirmation, usually via email confirming signing up.

Drip marketing – a marketing strategy (usually refers to email marketing), according to which a series of messages are sent automatically to the recipients over time, depending on the actions they perform or a specific schedule.


Email campaign – a single or a sequence of emails that are sent to the recipients to offer a deal, promote something, or as a part of a nurturing strategy, etc.

Email finder – a tool that helps find email addresses of leads or prospects on their websites, directories, social networks, etc.

Email verification – aka email validation, is the process of checking whether an email address is valid and active, during which domain check, syntax check, and an email ping are performed.

ESP – aka Email Service Provider, is a company providing email services, either specifically for email marketing, or for general public, like Gmail, Yahoo!, etc. Can be free or paid, usually has email sending limits.


Fallback image – an image that is displayed in the email message if the ESP doesn’t support HTML5.

Fallback font – a font that is displayed in the email message if the ESP doesn’t support your web font.

Footer – the bottom line in an email where additional sender information and opt-out options can be found.


GDPR – the General Data Protection Regulation established within the EU for individuals’ data protection. It forbids usage of a person’s data without their consent. For compliance in ecommerce, double opt-in is required.

Greylisting – anti-spam method that temporarily blocks the emails received from unknown senders. The mail transfer agent using greylisting will first reject the email from an unknown source. Non-spamming server will try to resend the message after a delay, after which it will be accepted.


Hard Bounce – a message returned to the sender because an email address is invalid or non-existent.

HTML message – an email that is designed to be more attractive than plain-text emails, using HTML to display templates, images, GIFs, videos, etc.


Invalid email – an email address that doesn’t exist or is not formatted according to internet email format standards (displaced @-symbol, unsupported language, etc.)

IP Address – a numerical id assigned to every device within the network. It is used to define and rate email senders from all over the world.


Layout – the design that defines the elements’ position in the email.


Marketing automation – the process of organizing your email marketing communication with the prospects in a way that does not require your direct participation. For example, welcome emails that are sent automatically when a person signs up, or onboarding emails send to a user as they explore features on your website. Drip campaigns are also used for email marketing automation.


Open rate – the percentage of campaign emails that have been opened. The open rate is counted by dividing the number of opened emails by the number of delivered emails and multiplying that number by 100.

Opt-In – or a “subscribe”, is the option for a person to join a certain email campaign or receive emails from a specific source on a regular basis.

Opt-Out – or an “unsubscribe”, is the option that allows the recipient to refuse any emails from you. It is obligatory under multiple regulations that an opt-out option is available within every marketing campaign email.


Personalization – a process of editing or tailoring your email for a specific person by using information about that person in an email message, such as addressing them by name, surname, talking about the company they work for, mentioning their position, etc. It has been proven that personalized messages perform better.

Plain text – an email that consists of text only, without the use of HTML. Such emails are considered to look more personal when used for marketing.

Prospect – a potential customer; a person to whom you send email campaigns, but who hasn’t been converted yet.


Segmentation – a process of dividing your campaign recipients list into separate groups according to some parameter(s), like age, gender, location, interests, etc. This technique is used for creating a more targeted and relevant email campaign.

Signature file – a file at the end of an email that contains all the info about the sender necessary for further contact (name, surname, company and position, contact information and company website).

SMTP – aka Simple Mail Transfer Protocol, is the mail protocol that is used for sending emails between servers or a server and mail client. Usually used for sending bulk emails to avoid ESP limits.

SMTP bounce codes – the codes presented by mail servers denoting why sent emails weren’t accepted.

Soft bounce – a situation when an email message is not delivered due to some temporary problems (like full mailbox or server problems). Soft bounce is different from a hard bounce in that the email address the message is sent to is valid.

SPAM – undesirable, unsolicited emails that are sent in bulk to recipients regardless of their interests.

Spam traps – email addresses used for luring spam senders. They do not belong to people, they are created by ESPs and blacklist providers to honeypot spammers.


Tracker – an app that allows its users to find out what happens to the emails after they are sent: whether they have been opened, how many times, and whether the links have been clicked.

Transactional email – an email sent to the user or a subscriber as a part of an email campaign but doesn’t promote anything. The examples of such emails are welcome and goodbye emails, reminders and notifications, etc.


Valid email – an existing email to which you can send your email campaign.


Welcome email – is an email or a series of emails that are sent to new users or subscribers. Used for establishing a good relationship with the newcomers, and improving conversion.

Whitelist – a list of IPs and email addresses that do their email campaigns correctly, meaning their campaigns get to the recipients’ inboxes and are not blocked by ESPs and spam filters.

read and download a free pdf

Leave a Reply (0)

Copied to clipboard