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Please accept our apologies in advance! As email marketers, we use a lot of fancy words and technical jargon. We’ve compiled this glossary to explain what these terms mean so you can learn the lingo of email marketing! We invite you to bookmark this page for future reference and also send suggestions to for words or phrases you think we should add or revise.
 

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A|B split testing, also called split testing, is a method for comparing two versions of an email to see which one performs best. Some common email split test variables are from names, subject lines, pre-headers, calls to action, layouts or message timing. The results learned from split tests can be used to increase opens, click-through rates and conversions over time. See also multivariate testing.
An activation email is designed to encourage a new email subscriber to make their first purchase.  Many brands use discounts or other special offers to incentivize the subscriber’s first purchase. (See also reactivation email).
Address book whitelisting happens when a subscriber adds your organization’s “from” email address to his or her email contacts/address book, which in turn alerts their email service provider that they really want to receive messages from your address. We encourage all email marketers to ask subscribers to whitelist the email address you routinely send from to help ensure your messages bypass any spam filtering and head straight to the inbox. See also whitelist.
Affirmative consent, also called express consent, is a proactive request by a user to receive promotions or newsletters via email. Affirmative consent means a subscriber must choose to check a permission box (not be given the option to uncheck a pre-checked box) on an online form. Automatically being added to an email list after purchasing a product violates affirmative consent. Affirmative consent is required under Canada’s Anti-Spam Legislation and several other countries’ email marketing regulations.
An alt tag is an HTML tag that specifies a short description or sentence that appears in the place of an image if the image is blocked or unavailable. Images are sometimes blocked by an email client, or they might be unavailable if the user isn’t connected to the internet.

An API, or application programming interface, is a set of routines, protocols and tools that allow different technologies to integrate with each other. In email marketing, we often use APIs to integrate your existing web forms and in-house databases with your email marketing platform. For example, a sign-up form on your website is typically connected to your email marketing platform through an API so that when a person signs up online to receive emails, they are automatically added to your email marketing list. Another example would be an API that allows you to share a subscriber profile update, such as a name change, from your master database to your email platform.

Email authentication refers to multiple methods that internet service providers (ISPs) use to confirm whether an email sender is who they say they are and whether the sender is allowed to send from a particular domain or IP address. See also Domain Keys Identified Mail, Sender Policy Framework and DMARC.
Batch and blast, also called broadcasting, means sending the same email to a large volume of recipients at the same time.
A blacklist is a list of the domains or IP addresses of any email senders suspected of sending spam. Many corporate and consumer mailbox providers use blacklists to filter out unwanted inbound email.
A bot is a software application that performs automated tasks. An internet bot performs these automated tasks, also called scripts, across the internet. Bots have been coded by spammers to harvest, or scrape, email addresses from websites across the internet.
A bounce occurs when an email message is undeliverable. Often, the recipient’s server will return a bounce message to the sender explaining why the message did not go through. There are a number of causes for bounces: server errors, use of an invalid or inactive email address, recipient’s mailbox is full, etc. A bounce can also be classified as a soft bounce or hard bounce. A soft bounce is a temporary delivery problem, such as a full mailbox. A hard bounce is a permanent delivery problem, such as an invalid address.
Bounce handling refers to how you or your email service provider (ESP) processes bounces. Most ESPs, for example, will allow at least three consecutive bounces before it flags a subscriber as invalid and stops sending to that address. This process is also referred to as list hygiene because it is an effective way to remove (or clean up) invalid email addresses from your list. Having too many invalid email addresses on your list can cause deliverability problems.
Bounce rate is the total number of bounced email addresses divided by the number of sent emails. This number is not exact because not all recipient servers send back messages, and if they do, the reason for the bounce is not always clear.
A break point refers to a screen width. Break points are set in the HTML of responsive emails to determine how the email should display on varying screen sizes. For example, a coder may set a screen width break point at 420. Using this break point, any screen wider than 420 pixels will display the desktop version of the email, and any screen narrower than 420 pixels will display the mobile version.
Broadcasting, also called batch and blast, is sending the same email message to a large volume of recipients at the same time.

Bulk email is the act of sending a large volume of email.

A bulk folder, also called a junk or spam folder, is a folder used to store unwanted and unsolicited email messages. Many email services use filtering mechanisms to automatically deliver email to a bulk folder instead of the inbox if they suspect it is spam or unwanted. Most email services allow users to set their own rules for diverting certain senders to the bulk folder as well.
Bulking is when a mailbox provider sends a large percentage of a sender’s mail to the recipients’ junk or spam folders instead of the inbox.
Buttons are graphic elements in HTML emails that contain a call to action and a visually obvious link.
Cadence describes the flow or pattern of an email campaign. It’s a combination of the number of messages sent to subscribers, the triggers for those emails and the spacing between them.
A call to action, or CTA, is a word or phrase that urges your subscribers to take an immediate action once they read your email. Some common calls to action include shop now, make a reservation, donate and learn more.

An email campaign is described as any email broadcast (newsletter, promotion, announcement, etc.) or series of broadcasts you send to your list of subscribers. The results of campaigns are often tracked and analyzed in aggregate and then used to improve future email marketing campaigns.

Campaign management is the entire process by which email marketing campaigns are planned, produced, distributed and reported. This includes concept creation, list acquisition and segmentation, writing, designing, editing, testing and deploying the email campaign and then reporting on the results.

This is the U.S. law that regulates commercial email. CAN-SPAM stands for “Controlling the Assault of Non-Solicited Pornography and Marketing Act of 2003.” Learn what every marketer needs to know about CAN-SPAM.
CSS is a coding method designers can use to define how different layout elements appear. With CSS, email designers can set up style sheets to control fonts, colors, spacing and more in their HTML.
CASL is Canada’s Anti-Spam Legislation. CASL is more restrictive than the United States’ CAN-SPAM legislation in that it requires marketers to get express consent to email subscribers versus using implied consent, where the subscriber already has a business relationship with the company or has made a purchase. Under CASL, implied consent expires two years after purchase date. Learn more about CASL.
A key performance indicator for email, click-through rate measures the percentage of email recipients who click on a specific link. Be sure you understand how your email platform defines this metric, as it can be calculated based on total emails sent or total non-bounced emails.
Click-to-open rate is the percentage of unique email openers who clicked on a link. CTOR can help you analyze the effectiveness of the calls to action visible after a subscriber opens the email.
A complaint occurs when a subscriber flags an email as spam or junk. If an email sender receives too many complaints, that sender’s online reputation and deliverability to the inbox is negatively affected.
The complaint rate is the rate at which the recipients of a specific email campaign register complaints with their mailbox providers. Gmail offers a “Report Spam” feature, for example, and other services have “Spam” or “Junk” buttons that make it easy for users to “complain” about specific senders.
Confirmed opt-in, also called double opt-in, requires new subscribers to take action, typically by clicking on an email link, to confirm their intent to begin receiving marketing emails.
The rate at which the recipients of a specific email campaign take action once they reach your landing page. The conversion action could be defined by purchasing a product, filling out a survey, signing up for a drawing, etc.
Co-registration is the practice of one organization offering subscriptions, memberships or leads to another organization on its own registration or subscription forms. This practice can be risky for email marketers because subscribers who join your list in this manner are more likely to opt out or file spam complaints, thereby negatively impacting deliverability to the inbox.
In email marketing, CPM is the cost to send a thousand emails.
The creative for an email campaign (or any marketing campaign, for that matter) refers to the concept, copy writing and graphic design. Learn more about Katey Charles Communications creative services.
Email deliverability refers to a marketer’s success at getting their marketing emails into their subscribers’ inboxes without getting caught in spam or bulk folders.
Delivered email is often calculated as the number of emails sent less the number of bounce messages received. But because not all recipient servers provide senders with accurate data on which emails didn’t go through and why, this is not an exact number. A better name for this term is non-bounced email.
Delivery rate is the number of delivered emails divided by the number of sent emails. We recommend taking action if a delivery rate drops below 98 percent. Because not all servers provide senders with accurate data on which emails didn’t go through and why, this is not an exact number. A better name for this term is non-bounce rate.
A digest newsletter is a shortened version of a newsletter that contains multiple headlines often combined with brief teasers. Each teaser typically hyperlinks to a web page, or landing page, where readers can view the entire article.
DMARC, or Domain-based Message Authentication, Reporting and Conformance, is an email authentication method that mailbox providers use to confirm whether emails are actually coming from the company or organization they say they are coming from. This method builds on DKIM and Sender ID/SPF Record methods that have been in place, and it adds an additional reporting component for senders.

 
To implement DMARC, you publish a DMARC record on your domain that tells receiving servers what to do with emails coming from your domain if they fail the DKIM or SPF test — do nothing, quarantine or reject. You also provide an email address where mailbox providers with DMARC can deliver reports about which emails are authenticating and which ones are not.

 
DMARC allows you to better prove that your email from address isn’t forged and can help free (think Gmail, Yahoo, Outlook.com) and corporate mailbox providers control inbound spam. It can help improve deliverability and establish (or maintain) a reputation for your sending domain. For more information about DMARC, visit dmarc.org.

A domain name is used to easily identify one or more IP addresses. It typically consists of two parts separated by dots. For example: kateycharles.com. Domain names are used in web addresses to identify web pages, and they are used in email addresses to identify sending and receiving IP addresses.

The Domain Name System, or DNS, is the internet database that translates domain names into IP addresses. Because domain names are alphabetic, they are easier for internet users to remember. But the internet is really based on IP addresses. Every time you use a domain name, therefore, a DNS must translate the name into the corresponding IP address. For example, the domain name www.sample.com might translate to 198.105.232.4.

A DNS record, or Domain Name System record, is a mapping file that identifies which IP address(es) your domain is associated with and what to do with requests that are sent to your domain. For example, an SPF record is a type of DNS record that tells receiving servers which IP addresses and/or other domains can send email using that domain.
DKIM is one of the authentication methods that mailbox providers use to confirm whether emails are actually coming from the company or organization they say they are coming from.

 
To implement this authentication method, you must add a “key,” or digital signature, to your message headers and to your DNS record so that recipients’ mail servers can verify your identity.

 
DKIM allows you to prove that your email from address isn’t forged and can help receiving servers like free email services (Gmail, Yahoo, Outlook.com, for example) and corporate email servers control inbound spam. It can help improve deliverability and establish (or maintain) a reputation for your sending domain. For more information on Domain Keys, visit dkim.org.
Double opt-in, also called confirmed opt-in, requires new subscribers to take action, typically by clicking on an email link, to confirm their intent to begin receiving marketing emails.

Email messages that incorporate dynamic content include graphic and text elements that change from one subscriber to the next depending on preset variables or rules. Different content could be determined by where recipients live, their purchase habits or the database list segments they belong to, for example.

An email client is a software program or app used to access and manage email. Some popular email clients include Outlook, Mail, the iPhone native email app and web-based clients like Gmail, Yahoo and Outlook.com.
An e-newsletter is a newsletter sent via email on a regular schedule to subscribers.
An email service, also called a mailbox provider or an inbox provider, is an organization that provides email hosting and email inboxes for its users. It provides email servers to send, receive, accept and store email. They can be one of the free services often used for personal email, like Gmail, Outlook.com and Yahoo, or paid services like Microsoft Exchange, which is used by many businesses.

An email service provider, also called an email vendor, is a third-party service that sends bulk and triggered email on behalf of its customers.

An email template is a predesigned layout that contains all the components of your email design that you plan to use repetitively. At a minimum, an email template typically includes a header graphic, a variety of content modules with predetermined formatting styles and a spam-compliant footer. Using a template saves time on production and keeps formatting and branding consistent.

The number of emails sent on a monthly or annual basis. Generally, the higher the email volume, the lower the cost per thousand (CPM) rate.
Engagement is an important measure of the success of your email campaigns. Engagement takes into account your open and click rates. A highly engaged subscriber list is far more likely to open, read and click on your email than a non-engaged list. Sending too many emails to non-engaged subscribers can hurt deliverability.
Express consent, also called affirmative consent, is a proactive request by a user to receive promotions or newsletters via email. Express consent means a subscriber must choose to check a permission box (not be given the option to uncheck a pre-checked box) on an online form. Automatically being added to an email list after purchasing a product violates express consent. Express consent is required under Canada’s Anti-Spam Legislation and several other countries’ email marketing regulations.
Fluid email design relies on percentage-based sizing to scale emails larger or smaller to fit different screen sizes. When using the fluid design technique, email content expands or contracts to fit the screen width upon which it is displayed. Learn more.
The footer refers to the area at the bottom of an email message that contains the same content from one email to the next, such as instructions for how to unsubscribe, disclaimers, copyright notices and company contact information.

Frequency is the number of times a subscriber receives an email message within a specific time period.
A from address is the email address from which a message is sent. Many people will not open an email unless they recognize the from address or at least the domain used in the from address. Also, some mailbox providers display the from name and from address in the inbox, while others show only the from name, so the two elements should be considered together from a branding perspective. Many organizations designate unique addresses for different types of messages, such as and See also from name.
A from name is a name or phrase paired with the sender’s email address, and it is dominantly displayed in recipients’ inboxes. A from name should clearly represent the individual, organization, company or brand. Without a from name, recipients will only see a from email address, which may not be immediately recognizable. From name is often called friendly from name. See also from address.
Harvesting email addresses, also called scraping, is the process by which a spammer uses a bot to “scrape” email addresses off of websites and add them to a database to be used for sending spam.
In general, a honeypot refers to a computer security mechanism used to detect unauthorized use of systems. In email marketing, a honeypot is an email address posted to a hidden web page to attract bots that are harvesting email addresses. Spammers who use honeypot addresses are then blocked by filtering and blacklisting services. See also spam trap.
A house list is one that a company or organization builds on its own via web forms, point of purchase, special events and other marketing activities without renting or purchasing third-party lists.

An HTML email is an interactive email message. It usually contains color graphics and links to web pages, or landing pages. HTML (Hypertext Markup Language) is the computer programming language used to build web pages as well as full-color, interactive emails. Most email marketing platforms offer editors that allow you to build an email easily without HTML coding experience.
Hybrid email design uses a combination of fluid and non-fluid HTML tables. Designers couple this coding strategy with media queries and Microsoft conditional comments to create email that looks great on Gmail and other email clients. Learn more.
Many email clients allow users to turn email images off, and some, notably many versions of Outlook, even turn them off by default. This helps emails load faster and can prevent viruses and malware. Image blocking also prevents email marketers from tracking opens accurately.

Email marketers assume they have received implied consent to add someone to their email list if they have an existing business or transactional relationship with that person — meaning they have purchased a product or service from their company. Implied consent is acceptable in the United States, but many other countries require affirmative, or express, consent for email marketing.
An inbox provider, also called an email service or a mailbox provider, is an organization that provides email hosting and email inboxes for its users. It provides email servers to send, receive, accept and store email. They can be one of the free services often used for personal email, like Gmail, Outlook.com and Yahoo, or paid services like Microsoft Exchange, which is used by many businesses.
Internet service providers, such as Comcast, AT&T, Charter and others, provide you with a connection to the internet. Many also offer their own web-based email services and email clients.
An invalid email address either is not functional because it is no longer in use, or it contains errors. The most common errors are typos like a missing @, period or domain extension, or a misspelled domain extension. Many ESPs flag email addresses as invalid if emails sent to them bounce three times in a row.
Every server, printer, computer, tablet or other electronic device that is connected to the Internet has an identifying IP address, or internet protocol address, made up of a series of four numeric values separated by periods. Example: 0.000.000.0.

In email marketing, your sending reputation (and therefore, your chances of reaching the inbox) is tied to the reputation of the IP address from which you are sending your messages. A dedicated IP address can only be used by one sender. Thus, many companies elect to purchase or “rent” a dedicated IP address from their email service provider so that their sending reputation cannot be influenced by other senders.
In email marketing, a shared IP address is used by many senders. If one of the senders gets blocked by a spam filter, it’s likely all senders sharing the same IP address will be blocked.
Warming up an IP address is the process by which a sender using a new dedicated IP address slowly increases its volume over time in order to establish good sending reputation with internet service providers.
A junk folder, also called a spam or bulk folder, is a folder used to store unwanted and unsolicited email messages. Many email services use filtering mechanisms to automatically deliver email to a junk folder instead of the inbox if they suspect it is spam or unwanted. Most email services allow users to set their own rules for diverting certain senders to the junk folder as well.
A key performance indicator, or KPI, is a quantifiable measure used to evaluate success in meeting objectives. In email marketing, the most common KPIs are open rate, click-through rate, click-to-open rate, bounce rate, non-bounce rate (sometimes called delivery rate), complaint rate, opt-out rate, conversion rate and return on investment.
A landing page is a web page that is linked to, or landed on, directly from a hyperlink in an email campaign. For example, the reader might find more information, register for an event, fill out a survey or make a product purchase on a landing page. Sometimes a unique mini-site, or group of landing pages, is built to support an email campaign. Other times, an email campaign links to already existing web pages.
Customer lifecycle refers to the length and nature of a customer’s relationship with your brand or company. Customers experience different phases throughout their lifecycle with your brand — including inquiry, consideration, selection and purchasing, usage and support, and replenishment or additional purchases. Lifecycle messages are targeted to the unique phase of the customer in the lifecycle. For example, a customer who purchases a car could receive an email campaign educating the customer about the unique features of that make and model of car and reminding them to complete their routine maintenance. As the car ages, marketers might send emails related to the estimated trade-in value of the vehicle or features of newer models.
If your organization sends too many emails or the same email multiple times, this may cause list fatigue, or diminished engagement by your subscribers. They are literally tired of hearing from you!
List hygiene, also called bounce handling, refers to how you or your email service provider process bounces in order to keep your list “clean.” Most ESPs, for example, will allow at least three consecutive bounces before it flags a subscriber as invalid and stops sending to that address. List hygiene is important because having too many bounced email addresses on your list can cause deliverability problems.
A list rental is the process by which a company pays a list owner to send an email message to that list. List rentals can result in deliverability problems because people who haven’t given you permission to email them typically register complaints and unsubscribe at high rates.
A mailbox provider, also called an email service or an inbox provider, is an organization that provides email hosting and email inboxes for its users. It provides email servers to send, receive, accept and store email. They can be one of the free services often used for personal email, like Gmail, Outlook.com and Yahoo, or paid services like Microsoft Exchange, which is used by many businesses.
A media query is a cascading style sheets (CSS) coding technique that allows HTML emails to adapt their layout based on screen size. Media queries are used in responsive email design.
Multivariate testing is a way of testing emails in which multiple elements — from names, from addresses, subject lines, content and send times — can be tested at the same time. The goal is to determine which combination of variables, of all possible combinations, performs best. See also A|B split testing.
A non-bounced email is one for which your server did not receive a bounce message. It is often assumed that non-bounced emails were delivered, but it’s important to understand that non-bounced emails may be delivered to the inbox, routed to a junk folder, or simply not received at all. See also bounce.
Non-bounce rate is the number of sent emails for which your subscribers’ servers did not receive a bounce message divided by the number of sent emails. We recommend taking action if a non-bounce rate drops below 98 percent. The non-bounce rate is also often called delivery rate, but non-bounce rate is the more accurate term.
The open rate is the percentage of non-bounced emails that are opened by subscribers. It should be a percentage of those emails delivered, not just those sent, as not all sent emails can be delivered.
Opting in is the process by which a subscriber elects to receive information and/or advertising via email from your company or organization. Ideally, this request should be obtained via a web form so that the permission is recorded electronically. See also permission-based email, express consent and implied consent.
An opt-in email list is made up entirely of subscribers who have given permission for your organization to send marketing messages. Opt-in lists are also called permission-based email lists.
Opting out, or unsubscribing, is the process by which a subscriber to your email list chooses to no longer receive marketing email from your company or organization. In the U.S., CAN-SPAM laws require organizations to offer a way to opt out of your marketing emails. Marketers should include an obvious opt-out, or unsubscribe, link in every email sent.
The opt-out rate is the rate at which the recipients of a specific email campaign opt out, or unsubscribe, from your list.
Permission-based email campaigns are those sent only to voluntary subscribers — those who have given their permission to receive marketing messages from your company or organization via email.
A permission-based email list is made up entirely of subscribers who have given your organization consent to send marketing messages. Permission-based email lists are also called opt-in lists.
Email marketing messages can be personalized with a variety of subscriber profile and behavioral data points. For example, you could personalize a message with a subscriber’s first name, a product they recently browsed on your site and the store location nearest to their ZIP code. Personalized emails are more relevant to individual subscribers and generally yield higher open, click and conversion rates.
Phishing is an identity theft scam in which spammers use an authentic-looking email to trick recipients into providing personal information such as credit card numbers or social security numbers. See also spoofing.
A plain-text email is an email message containing only text with no special fonts, graphics, color or detailed formatting. It can contain links to landing pages. Plain-text email is also called text-only email.
Pre-header text is a sentence or two that appears at the top of an HTML email. It’s coded to display prominently adjacent to the subject line in the inbox of most mobile and desktop email clients, making this copy strategically vital for boosting email open rates.
A preview pane, or a reading pane, allows inbox users to preview messages without fully opening them. Email opens are tracked by an image that loads when the email loads, so even if the message loads into a preview pane, email service providers can track it as an open.
A privacy policy is a clear description of how your organization uses any data collected about its customers, members or users. It should be posted to your website and should include information about how you handle email addresses and other data collected on your website or through other means. If you share or sell email addresses with third parties, this must be stated in your privacy policy.
A reactivation email is designed to encourage a customer to make an additional purchase. Many brands use discounts or other special offers to incentivize repeat purchases. (See also activation email.)
Rendering is how an HTML email displays across email clients and devices. Your email may look unexpectedly different on various email clients. There are several services that allow you to test how your message renders on the most common mobile, web-based and desktop clients. We also recommend checking rendering by sending test messages directly to as many email clients and devices as possible.
Whereas a from address indicates to the recipient who a message is from, the reply-to field defines the email address that will be inserted into the “to” field if a recipient replies to the message. For most messages, the from and reply-to addresses are the same, but there are times when a different reply-to address makes sense. For example, if your from address belongs to your CEO, you might want the reply-to address to be for a marketing or customer service associate.
Responsive email design is an approach to HTML email coding that detects the recipient’s screen size and orientation and adjusts the layout accordingly. The technique makes use of media queries and layouts that adjust or “stack” on smaller devices.
ROI, or the return on investment, is a performance measure used to evaluate the efficiency of an investment. To calculate ROI, the benefit (or return) of an investment is divided by the cost of the investment, and the result is expressed as a percentage. In email marketing, because you can track purchases made via your email campaigns, you can accurately calculate the monetary return on your investment for any campaign. There are other ways to measure the success of your promotions, too. For example, you might measure your ROI by tracking the number of sales leads or new subscriptions generated. See also conversion rate.
Rich media refers to the use of video, audio or other elements that encourage greater interaction with digital media.
Scraping email addresses is the process by which a spammer uses a bot to gather email addresses off of websites and add them to a database to be used for sending spam. Scraping is also called harvesting.
A seed list is a list of email addresses used for testing an email campaign. Addresses from the list are added to every sent email and can be monitored to see how a message renders across email platforms and whether the message is delivered to the inbox or a junk folder. We do not recommend relying solely on an internal seed list for monitoring deliverability, but it is a great tool for checking rendering.
An email segment is a list of subscribers who meet common criteria. For example, you might have separate segments in your email database for different brands, or for subscribers who have signed up to receive different newsletters. Segments can be determined by demographics, profile data or behaviors. Subscribers can often be found in more than one segment in an email database.
Sender Policy Framework, or SPF, is one of the authentication methods that mailbox providers use to confirm whether emails are actually coming from the company they say they are coming from.

 
To implement SPF, you add an SPF record to your Domain Name System (DNS), indicating which IP addresses or domains you have given permission to send messages on your behalf. Then, when an email is sent, the recipient’s inbound mail server checks the email to see whether the domain name in the “from” field of your message matches any of the domains listed in the SPF record. If there is a match, the mail is authenticated and delivered to the recipient. If there is not a match, the mail fails authentication and is not delivered.

 
SPF allows you to prove that your email from address isn’t forged and can help receiving servers like free email providers (Gmail, Yahoo, Outlook.com, for example) and corporate email servers control inbound spam. It can help improve deliverability and establish (or maintain) a reputation for your sending domain. For more information about the Sender Policy Framework, visit www.openspf.org.
An SPF record is a domain record that indicates which IP addresses or domains are allowed to send emails from that domain. In order to implement Sender ID email authentication, the domain sending emails must publish an SPF record in its DNS. This SPF record should include the domains of any third-party email service providers. When an email is sent, the recipient’s inbound mail server checks the email to see whether the domain name in the “from” field of the message matches any of the domains listed in the sender’s SPF record. If there is a match, the mail is authenticated and delivered to the recipient. If there is not a match, the mail fails authentication and is not delivered.

 
If you are using a third-party email service provider to send emails, ensure that you post the service provider’s domains in your SPF record.
Tied to the email sender’s IP address, a sender reputation determines how trustworthy that IP address is to mailbox providers. Mailbox providers, also called inbox providers or email services, consider spam complaints, industry blacklists and other metrics when determining whether a marketer’s sender reputation is positive or negative. If you have a bad sender reputation, your email will be delivered to the junk or spam folder or not delivered at all.
SMTP is a protocol for sending email messages between servers. Most email systems that send mail over the Internet use SMTP to send messages from one server to another.
Social share buttons allow subscribers to share an email or a website on their social networks. This should not be confused with social follow links that encourage subscribers to follow the brand on various social networks.
A spam message is an unsolicited, usually commercial, email message. It is also referred to as unsolicited commercial email (UCE). The U.S. definition of spam is defined by the CAN-SPAM Act of 2015. See also CAN-SPAM.
A spam filter is any program or method used to keep spam out of an inbox. Spam filters can operate at the user level (a user blocks a sender in Outlook, for example), at the corporate level (an IT department sets up a filter to protect employees from spam) or at the mailbox provider level (Gmail and Comcast each have their own filtering rules, for example).
A spam folder, also called a junk or bulk folder, is a folder used to store unwanted and unsolicited email messages. Many email services use filtering mechanisms to automatically deliver email to a spam folder instead of the inbox if they suspect it is spam or unwanted. Most email services allow users to set their own rules for diverting certain senders to the spam folder as well.
A spam trap, also called a honeypot, is an email address used by an email provider’s filtering engine to detect spammers. For example, an email provider might post a spam trap address to a hidden web page, which can then be harvested or scraped by a bot. If anyone sends messages to the spam trap address, the email service will block this sender because they know they are harvesting addresses.
Spoofing is a technique used by spammers that forges an email header to make it appear as if it came from somewhere or someone other than the actual source. Spoofing is often used in conjunction with phishing.
A headline, description or sentence written to tell subscribers what an email is about. It should be written to entice recipients to either open the email or take another action. In most inboxes, the subject line appears to the right of the from name and from address.
According to CAN-SPAM law, each company or organization is required to maintain a suppression file, or a list of those who have unsubscribed or requested to be removed from your email list. When switching email service providers, the suppression file should be moved along with all other list data.
An email teaser is a short paragraph written to encourage subscribers to click through to a web page, or landing page.
A text-only email is an email message containing only text with no special fonts, graphics, color or detailed formatting. It can contain links to landing pages. Text-only email is also called plain-text email.
A transactional email is a one-to-one email used to complete a transaction that the recipient initiated. Purchase receipts, shipping notifications, payment reminders, password changes and account updates (as in, Joe Smith has connected with you on LinkedIn) sent after a transaction has occurred are transactional emails. Be aware that different countries allow different content in transactional emails. In the U.S., for example, you can include some marketing content in your transactional emails as long as the primary purpose of the email is transactional in nature. In Canada, however, if you include any marketing content, the message would be classified as a marketing message and subject to marketing email regulations requiring express consent. Here is a good explanation of the differences between marketing and transactional emails.
A triggered email, also sometimes called an auto-responder, is sent only after a subscriber takes a specified action or meets pre-determined criteria. For example, a welcome email is a triggered email that is sent immediately after a subscriber joins the list. A birthday email is a date-triggered email that is sent on or near a subscriber’s birthday. Transactional emails are triggered by a purchase or another action on an e-commerce site. Triggered emails, because they are so relevant to individual subscribers, typically generate much higher engagement and conversions than regular marketing emails. Learn more about triggered email.
A URL is a web address for a web page. For example, http://www.kateycharles.com is a URL.
UCE is a spam message, or an unsolicited, commercial, email message. The U.S. definition of spam is defined by the CAN-SPAM Act of 2015.
Unsubscribing, or opting out, is the process by which a subscriber to your email list chooses to no longer receive marketing email from your company or organization. In the U.S., CAN-SPAM laws require organizations to offer a way to opt out of your marketing emails. Marketers should include an obvious unsubscribe, or opt-out, link in every email sent.
A view online link allows subscribers to click to view your email in a web browser. This link helps subscribers who have display issues with their email client, like blocked images.
Webmail is an email client accessed via a web browser. Examples of webmail providers are Gmail, Outlook.com and Yahoo! Mail. Many webmail providers also offer email access by a desktop email client, while many internet service providers include a webmail client as part of the email service associated with their internet service package.
A whitelist is a list of “accepted” email addresses that an internet service provider, a subscriber or other email service allows to reach the inbox regardless of spam filter settings. See also address book whitelisting.