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A
Autoresponder: An automated email message that is sent in response to a user's action or trigger, such as signing up for a newsletter or completing a purchase.
A/B Testing: A method of comparing two versions of an email message or campaign to determine which one performs better, typically by testing different subject lines, content, or calls-to-action.
Attachment: A file or document that is attached to an email message and sent along with the email content.
Authentication: The process of verifying that an email message was sent from a legitimate sender and has not been modified or tampered with during transmission, typically using methods such as SPF, DKIM, and DMARC.
Anti-Spam: A software or system designed to prevent or filter out unwanted or unsolicited email messages, often using techniques such as content filtering, blacklisting, and whitelisting.
Above the Fold: The portion of an email message or webpage that is visible without requiring the user to scroll down or click on a link. Content placed above the fold is considered more likely to be viewed and engaged with by users.
Abuse Complaint: A report or notification from a recipient or email service provider indicating that an email message is unwanted or unsolicited, typically resulting in a decrease in sender reputation or deliverability.
API: An abbreviation for Application Programming Interface, a set of protocols, routines, and tools used to build software applications and allow different systems to communicate with each other, often used in email marketing to integrate with other platforms and services.
B
Bounce Rate: The percentage of email messages that are returned or 'bounce' back to the sender due to a delivery issue, such as an invalid email address or a full mailbox.
Blacklist: A list of email addresses, domains, or IP addresses that have been identified as sending spam or unwanted email messages, often used by email service providers to block or filter incoming messages.
Block List: Another term for blacklist, used to describe a list of email addresses, domains, or IP addresses that are blocked or prevented from sending email messages to a particular recipient or service.
Backscatter: Backscatter in email industry refers to the process where an email server receives and sends non-delivery reports (NDRs) for emails that were not successfully delivered. These NDRs are sent to the apparent sender of the email, even if the email was sent from a forged or fake address. Backscatter can be caused by email spam and phishing attacks, and it can negatively impact email deliverability by causing legitimate email messages to be marked as spam. Email servers can use techniques like Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM) to prevent backscatter by verifying the sender's identity before sending NDRs.
Backscatter: Backscatter in email industry refers to the process where an email server receives and sends non-delivery reports (NDRs) for emails that were not successfully delivered. These NDRs are sent to the apparent sender of the email, even if the email was sent from a forged or fake address. Backscatter can be caused by email spam and phishing attacks, and it can negatively impact email deliverability by causing legitimate email messages to be marked as spam. Email servers can use techniques like Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM) to prevent backscatter by verifying the sender's identity before sending NDRs.
Bulk Email: An email message sent to a large group of recipients at once, typically used for marketing or promotional purposes.
Behavioral Email: An email message that is triggered or sent based on a user's behavior or interaction with a website or application, such as a welcome email or abandoned cart reminder.
Branding: The use of visual and messaging elements to establish and promote a company's identity and reputation, often applied to email marketing through the use of logos, colors, and consistent messaging.
B2B: An abbreviation for business-to-business, a type of commerce that involves transactions between two or more businesses, often using email marketing to target specific industries or decision-makers.
B2C: An abbreviation for business-to-consumer, a type of commerce that involves transactions between a business and individual consumers, often using email marketing to promote products or services to a wider audience.
C
Click-Through Rate (CTR): The percentage of email recipients who clicked on a link or call-to-action in an email message, often used as a metric for measuring engagement and effectiveness.
Call-to-Action (CTA): A message or button included in an email message or webpage that encourages the user to take a specific action, such as making a purchase, signing up for a newsletter, or visiting a website.
CAN-SPAM: A law passed by the United States Congress in 2003 that sets rules and guidelines for commercial email messages, including requirements for opt-out mechanisms, accurate sender information, and clear labeling of promotional content.
Conversion Rate: The percentage of email recipients who completed a desired action or goal, such as making a purchase, signing up for a service, or filling out a form.
Confirmation Email: An automated email message sent to a user to confirm a subscription, account creation, or other action, often including a link or call-to-action to complete the process.
Content Filtering: The process of analyzing email messages for specific keywords, phrases, or other criteria to determine whether they should be delivered, blocked, or filtered into a specific folder or category.
Click-to-Open Rate (CTOR): The percentage of email recipients who clicked on a link or call-to-action in an email message after opening it, often used as a metric for measuring engagement and interest.
Customer Relationship Management (CRM): A software or system used to manage and analyze customer interactions and data, often used in email marketing to personalize and segment email campaigns based on customer behavior and preferences.
D
Deliverability: The ability of an email message to successfully reach its intended recipient's inbox, often impacted by factors such as sender reputation, content, and technical configuration.
Double Opt-In: A process for obtaining permission from email subscribers, in which users confirm their subscription by clicking on a link or replying to a confirmation email, typically considered a best practice for ensuring list quality and reducing spam complaints.
Data Segmentation: The process of dividing an email list into smaller, targeted groups based on factors such as demographics, behavior, or preferences, often used to personalize email campaigns and improve engagement and conversion rates.
Domain Name System (DNS): A system used to translate domain names (such as example.com) into IP addresses, enabling email servers to route messages to their intended destination.
DKIM (DomainKeys Identified Mail): A technical authentication method used to verify that an email message was sent from a trusted domain and has not been modified in transit, often used by email service providers to improve deliverability and prevent spam.
Drip Campaign: A series of automated email messages sent to subscribers over time, often used for lead nurturing or onboarding, and typically triggered by a user's behavior or inactivity.
Dynamic Content: Email content that is customized and personalized based on factors such as a user's location, behavior, or preferences, often used to improve engagement and conversion rates.
E
Email Client: A software program used to access and manage email messages, such as Microsoft Outlook, Gmail, or Apple Mail.
Email Marketing: The practice of using email to promote products, services, or content to a list of subscribers, typically with the goal of driving engagement, leads, or sales.
Engagement Rate: A metric used to measure how actively subscribers are interacting with email messages, typically calculated as a percentage of opens, clicks, or other user actions.
Email Service Provider (ESP): A company that provides email marketing and delivery services to businesses and organizations, often offering features such as list management, campaign design, and deliverability monitoring.
Email Validation: The process of verifying that an email address is valid and active, typically performed to reduce bounce rates, improve list quality, and prevent fraudulent or fake email addresses.
Email Workflow: The series of steps and actions involved in creating and sending an email campaign, often including tasks such as list segmentation, content creation, design, testing, and scheduling.
Email Deliverability: The ability of an email to successfully reach its intended recipient's inbox, often impacted by factors such as sender reputation, content, and technical configuration.
F
Forward-to-a-Friend (FTAF): A feature within an email campaign that allows subscribers to easily forward the email to others, typically used to increase reach and referral traffic.
Footer: The section at the bottom of an email message that typically includes legal disclaimers, contact information, and a link to unsubscribe from future messages.
From Address: The email address that appears in the 'From' field of an email message, indicating who the message is from.
Frequency: The number of email messages sent to subscribers within a specific period of time, often determined by factors such as content availability, user preferences, and marketing goals.
Feedback Loop: A service provided by some email service providers that enables email senders to receive notifications when recipients mark their emails as spam, allowing senders to remove those recipients from their lists and improve their sender reputation.
FBL (Feedback Loop): A program offered by ISPs and email service providers that enables email senders to receive notifications when their emails are marked as spam by recipients, allowing senders to remove those recipients from their lists and improve their sender reputation.
Focused Inbox: A feature within some email clients that automatically sorts and prioritizes incoming email messages based on factors such as user behavior, content, and sender reputation, often improving email management and productivity.
G
Graymail: Email messages that are not necessarily spam but are not actively engaged with by the recipient, such as newsletters or promotional offers that are no longer of interest.
Graymail: Email messages that are not necessarily spam but are not actively engaged with by the recipient, such as newsletters or promotional offers that are no longer of interest.
Graymail: Email messages that are not necessarily spam but are not actively engaged with by the recipient, such as newsletters or promotional offers that are no longer of interest.
Gmail Tabs: A feature within Gmail that automatically sorts incoming email messages into different tabs, such as Primary, Social, Promotions, Updates, and Forums, improving email organization and productivity.
Geo-Targeting: The practice of targeting email messages to subscribers based on their geographic location, often used to promote localized products, events, or offers.
GIF: A type of image file format that supports animation and is commonly used in email marketing to add visual interest and engagement to messages.
Gated Content: Content that requires users to provide their email address or other contact information before they can access it, often used in email marketing to generate leads and build lists.
Glitch: An unexpected error or technical problem that can occur in the sending, delivery, or rendering of email messages, often resulting in a poor user experience and reduced engagement.
H
Hard Bounce: An email message that is returned to the sender because it was undeliverable, typically due to an invalid or non-existent email address.
Header: The section at the top of an email message that includes information about the sender, recipient, subject line, and other metadata.
HTML Email: An email message that is formatted using Hypertext Markup Language (HTML), allowing for the inclusion of images, links, and other multimedia elements.
Hard Ask: A direct request made to email subscribers, often used in email marketing to promote a specific product, service, or offer.
Heat Map: A graphical representation of the engagement levels of different elements within an email message, such as the subject line, images, and links, often used to optimize email design and content.
Harvesting: The practice of collecting email addresses from websites, social media profiles, or other online sources without permission, often used by spammers and other malicious actors.
HTML: Hypertext Markup Language, the standard coding language used to create web pages and format HTML email messages.
I
Inbox: The main folder in an email client or webmail service where incoming email messages are delivered and stored.
IP Address: Internet Protocol Address, a unique numerical identifier assigned to every device connected to the internet, often used to track and identify the source of email messages.
Impressions: The number of times an email message or advertisement is viewed or displayed to an individual user, often used to measure the reach and effectiveness of email marketing campaigns.
Incentive: A reward or offer provided to email subscribers in exchange for taking a specific action, such as making a purchase or referring a friend.
ISP (Internet Service Provider): A company that provides internet access to individuals and businesses, often used to refer to the organizations responsible for delivering email messages to recipient inboxes.
Invitation Email: An email message sent to invite subscribers to attend an event, webinar, or other gathering, often used in event marketing and lead generation.
Inactive Subscriber: An email subscriber who has not engaged with email messages or taken any action in a significant amount of time, often targeted with re-engagement campaigns to maintain list health and improve email deliverability.
J
Journeys: A series of email messages designed to guide subscribers through a specific process or experience, often used in email automation to nurture leads or onboard new customers.
JavaScript: A programming language used to create dynamic and interactive web content, often used in email marketing to add interactive elements such as drop-down menus or sliders.
JPEG: Joint Photographic Experts Group, a popular image file format often used in HTML emails.
Jargon: Technical language or terminology specific to a particular industry or profession, often avoided in email marketing to improve clarity and readability for subscribers.
Junk Folder: A folder in an email client or webmail service where suspected spam messages are automatically filtered and stored, often requiring manual review by the recipient to identify legitimate emails that were incorrectly categorized.
Jet Stream: A Gmail feature that enables high-volume senders to securely send large quantities of email messages while maintaining email deliverability and reputation.
JSON: JavaScript Object Notation, a lightweight data interchange format used to transmit data between web servers and applications, often used in email marketing to personalize email content and improve subscriber engagement.
K
KPI: Key Performance Indicator, a measurable value used to evaluate the success or effectiveness of an email marketing campaign or strategy.
Keyword: A word or phrase used to identify specific content or topics within an email message or email marketing campaign, often used in email search functionality.
Known Sender: A sender who is recognized by the email recipient and has an established reputation for sending relevant and trustworthy email messages.
Kiosk Mode: A feature in some email clients or webmail services that enables users to access and view email messages without accessing other applications or functionality on their device.
Kill Switch: A feature that enables email marketers to immediately stop or pause an email campaign if necessary, often used in emergency situations or to prevent the delivery of a faulty email message.
K-form: A type of online form used to capture email subscriber information, often used in email list building and lead generation.
K-factor: A metric used to measure the viral potential of an email marketing campaign or message, often based on the number of new subscribers generated through referrals or sharing.
L
Landing Page: A dedicated web page designed to capture visitor information or guide them toward a specific action, often used in email marketing campaigns to increase conversions.
List Segmentation: The process of dividing an email list into specific segments based on shared characteristics or behaviors, often used to improve email personalization and targeting.
Lead Magnet: An incentive or offer used to entice email subscribers to provide their contact information or engage with an email marketing campaign.
List Building: The process of growing an email list by adding new subscribers through various means such as lead magnets, opt-in forms, and social media campaigns.
List Hygiene: The practice of regularly cleaning an email list to remove invalid or inactive email addresses, spam traps, and other unwanted contacts, often used to improve email deliverability and engagement rates.
Lifecycle Emails: A series of automated email messages designed to engage and nurture email subscribers at various stages of the customer journey, from welcome messages to retention and re-engagement campaigns.
Link Tracking: The process of monitoring and analyzing clicks on links within email messages, often used to measure email engagement and campaign effectiveness.
M
Mail Merge: The process of combining a template email message with a list of personalized recipient information, often used in email marketing campaigns to create customized messages at scale.
Multi-Part MIME: A format for sending email messages that includes both HTML and plain text versions of the email, allowing recipients to view the email in the format they prefer.
Metrics: Measurable data used to track and analyze the performance of email marketing campaigns, such as open rates, click-through rates, conversion rates, and revenue generated.
Mobile Optimization: The process of designing email messages and landing pages to be easily viewed and interacted with on mobile devices, often essential for successful email marketing campaigns.
Microsite: A small website designed to provide targeted content and a specific call to action, often used in email marketing campaigns to increase conversions.
Mailing List: A collection of email addresses used to send email marketing messages to subscribers, often managed through an email service provider.
Message Transfer Agent (MTA): A software application responsible for routing and delivering email messages between mail servers, often used in email infrastructure management.
N
Newsletter: A regularly distributed email containing news, updates, and information about a particular topic or industry, often used in email marketing campaigns to engage subscribers and build brand awareness.
Nurture Campaign: A series of automated email messages designed to nurture leads and guide them through the customer journey, often used to improve lead conversion rates and increase customer retention.
NPS (Net Promoter Score): A customer satisfaction metric used to measure how likely customers are to recommend a business, product, or service to others, often used in email surveys and feedback requests.
O
Opt-in: The process of obtaining explicit permission from a subscriber to receive email marketing messages, often through an opt-in form or confirmation email.
Open Rate: The percentage of email recipients who open a given email message, often used as a key email engagement metric.
Organic List Growth: The process of growing an email list through natural means, such as word-of-mouth referrals, content marketing, and social media sharing, without the use of paid advertising or list rental.
Out-of-Office (OOO) Message: An automated email response sent to correspondents when the recipient is not available to respond to email messages, often used to set expectations and provide alternative contact information.
Opt-out: The process of allowing recipients to unsubscribe from receiving email marketing messages, often through an unsubscribe link or email preference center.
Open Tracking: A method of tracking email opens by inserting a small, transparent image into an email message that sends a signal back to the sender when the email is opened.
Onboarding: The process of introducing new subscribers or customers to a business or product, often through a series of automated welcome emails or other communication.
Email Overlay: A pop-up window that appears over an email message, often used in email marketing campaigns to promote a special offer or call to action.
Organic Reach: The number of email recipients who receive and engage with an email message through natural means, such as opening the email and clicking on links, without the use of paid advertising or promotion.
Order Confirmation Email: An automated email message sent to customers after completing an online purchase, confirming the details of the transaction and providing a receipt.
Email Outreach: The process of sending email messages to potential customers or partners as a means of initiating contact and building relationships, often used in sales and marketing campaigns.
P
Personalization: The process of tailoring email content to individual subscribers based on their interests, behaviors, and preferences, often used to improve engagement and response rates.
Preview Text: The snippet of text that appears below or next to the subject line in an email client, providing a brief preview of the email content and often used to entice subscribers to open the email.
Promotional Email: An email message that promotes a product, service, or offer, often used in email marketing campaigns to drive sales and revenue.
Email Provider: A company or service that provides email hosting, delivery, and management tools for businesses and individuals, such as Gmail, Yahoo! Mail, or Microsoft Outlook.
Phishing: The fraudulent practice of attempting to obtain sensitive information, such as passwords and credit card numbers, by posing as a trustworthy entity in an email message or other communication.
Plain Text Email: An email message that consists only of text, without any images or HTML formatting, often used in transactional or personal email messages.
Post-Click Landing Page: The web page that a subscriber is directed to after clicking on a link in an email message, often used to drive conversions and sales.
Q
Quota: The maximum number of emails that an email sender is allowed to send or receive within a certain time period, often used by email providers to prevent spam and abuse.
R
Responsive Design: A design approach that enables email messages to adapt to different screen sizes and devices, ensuring that they display properly and remain readable on desktops, tablets, and smartphones.
Reputation: The perceived trustworthiness and credibility of an email sender, based on factors such as email volume, engagement rates, spam complaints, and other metrics, often used by email providers to filter and deliver emails.
Relay: The process of transferring email messages from one email server to another, often used by email providers to route and deliver emails to their intended recipients.
ROI: Return on Investment, a metric used to measure the effectiveness and profitability of email marketing campaigns by comparing the costs and revenue generated by the campaign.
RSS-to-Email: A service that enables publishers to automatically convert their RSS feeds into email messages, allowing subscribers to receive content updates directly in their email inboxes.
Re-Engagement Campaign: A targeted email campaign designed to re-engage inactive subscribers and encourage them to become active again, often by offering incentives or asking for feedback.
Rendering: The process of displaying email content in an email client, browser, or other device, ensuring that it is presented accurately and attractively to the recipient.
S
SPF: Sender Policy Framework, an email authentication protocol that verifies the origin of email messages by checking the sender's domain name and IP address against a list of authorized senders.
Segmentation: The process of dividing an email list into smaller groups based on specific criteria such as demographics, interests, behaviors, and other factors, allowing marketers to create targeted and personalized email campaigns.
Soft Bounce: A temporary email delivery failure that occurs when an email message is returned to the sender due to a temporary issue such as a full mailbox or a server error.
Spam: Unsolicited or unwanted email messages that are sent to a large number of recipients, often with the intent to advertise or promote a product or service.
Spam Complaint: A report by an email recipient indicating that they received unsolicited or unwanted email, often used by email providers to monitor and filter spam.
Subscriber: An individual who has opted-in to receive email messages from an email sender or email list, often by filling out a subscription form or providing their email address.
Suppression List: A list of email addresses or domains that have been opted-out or unsubscribed from receiving email messages from an email sender, often used to prevent sending emails to individuals who have previously complained or unsubscribed.
Subject Line: The headline or title of an email message that appears in the recipient's inbox, often used to grab the recipient's attention and entice them to open the email.
Spam Filter: A tool or software program used by email providers to identify and filter out spam and unwanted email messages, often using a variety of algorithms and rules.
T
Template: A pre-designed and formatted email layout that can be customized with text, images, and other elements, often used to save time and ensure consistency across email campaigns.
Transactional Email: An automated email message triggered by a specific action or event, such as a purchase confirmation or password reset, often used to deliver important information to recipients.
Test Email: A trial email message sent to a small group of recipients or to oneself to test and review the email content and design before sending to a larger audience.
Text-Only Email: An email message that consists only of plain text, without any HTML or formatting elements, often used for simpler and more straightforward communication.
Time Zone Sending: A feature of email marketing software that allows marketers to schedule email campaigns to be sent at specific times based on the recipient's time zone, increasing the likelihood of the email being opened and read.
Trigger: An event or action that automatically initiates an email message, such as a purchase or a form submission, often used to deliver relevant and timely content to recipients.
Transactional Email Service Provider (ESP): A provider of specialized email services that focuses on the delivery and management of transactional email messages, often used by businesses to ensure timely and reliable delivery of important customer communications.
Tracking Pixel: An invisible image or code snippet embedded in an email message that allows the email sender to track and measure various metrics such as email opens, clicks, and conversions.
Target Audience: The specific group of individuals or customers that an email campaign is designed to reach and engage, often based on factors such as demographics, interests, behaviors, and other characteristics.
U
Unsubscribe: The action taken by an email recipient to opt-out of future email communications from a particular sender or email list, often required by law and considered best practice to honor recipient preferences.
User-generated Content (UGC): Content created and shared by users or customers, often used in email marketing campaigns to increase engagement and authenticity.
Unique Clicks: The number of individual recipients who clicked on a link within an email message, often used to measure the effectiveness and engagement of an email campaign.
Unique Opens: The number of individual recipients who opened an email message, often used to measure the reach and engagement of an email campaign.
Unengaged Subscriber: A recipient who has not interacted with or opened email messages from a sender or email list for an extended period of time, often targeted with re-engagement campaigns or removed from the list to maintain list hygiene.
URL: Uniform Resource Locator, a string of characters that identifies the location of a web page or resource on the internet, often used in email marketing to link to landing pages, product pages, or other online content.
User Experience (UX): The overall experience and satisfaction of a user or customer when interacting with a website, application, or digital product, often considered in email marketing design and strategy to improve engagement and conversion.
V
Verified Opt-In (VOI): A double opt-in process where a recipient must confirm their subscription to an email list by clicking on a link in a confirmation email, considered a best practice to ensure list quality and avoid spam complaints.
Viewport: The visible area of a user's screen or device, often considered in email marketing design to ensure optimal viewing and readability on various screen sizes and resolutions.
Vanity Metrics: Metrics that may look impressive but do not provide meaningful insights into the effectiveness of an email campaign, such as total number of subscribers or likes.
Value Proposition: The unique benefit or value that a product, service, or offer provides to a customer, often used in email marketing messaging and content to increase engagement and conversion.
Viral Marketing: A marketing strategy that relies on customers or users to spread a message or offer through word-of-mouth or social sharing, often used in email marketing campaigns to increase reach and engagement.
Visual Hierarchy: The arrangement and prioritization of design elements and content in an email message, often considered in email marketing design to ensure optimal readability and conversion.
Volume Email: High-volume email campaigns sent to large email lists, often used in email marketing to reach a large audience and increase brand awareness or sales.
W
Whitelist: A list of approved email senders or domains that are allowed to bypass spam filters and deliver emails directly to the recipient's inbox.
Web Beacon: A small, invisible image embedded in an email message or web page that allows email marketers to track open rates and user behavior.
Welcome Email: The first email message sent to a new subscriber after they sign up for an email list, often used in email marketing to welcome and introduce new subscribers to the brand or offer.
Warm-up Campaign: A series of email campaigns sent to a new email list or IP address to establish sender reputation and increase email deliverability.
Workflow: A sequence of automated actions and triggers that are initiated based on user behavior or certain conditions, often used in email marketing to automate and optimize campaigns.
WYSIWYG: Stands for 'What You See Is What You Get', a term used to describe a user interface that shows a visual representation of the final output, often used in email marketing design tools to allow users to design and edit email content visually.
X
XML (Extensible Markup Language): A markup language used to encode documents in a format that is both human-readable and machine-readable. XML is often used in email marketing to format and structure data in emails.
X-header: An additional header added to an email message that provides additional information about the message, such as email tracking or routing information.
XLIST: An IMAP extension used to retrieve folder lists from an IMAP server. This extension is used in email clients to display a list of folders available on the server.
X-Originating-IP: An email header that contains the IP address of the computer or device that sent the email message. This header can be used to trace the origin of an email message.
X-Spam: An email header added by spam filters that indicates whether an email message has been identified as spam. This header can be used to filter and sort incoming email messages.
Y
Yahoo! Mail: A popular web-based email service offered by Yahoo! Inc. that provides users with email, calendar, and contact management tools.
Yellow card: A warning email sent by an email service provider (ESP) to a sender who has violated the ESP's terms of service. A yellow card is typically issued before an account is suspended or terminated.
Yield management: The process of optimizing email campaign performance by adjusting the price and timing of email sends based on recipient engagement and other performance metrics.
YOY (Year Over Year): A performance metric that compares email campaign performance to the same period in the previous year. YOY analysis can help email marketers identify trends and patterns in email campaign performance over time.
YouTube email marketing: A marketing strategy that uses YouTube videos to promote products, services, or brands via email. YouTube videos can be embedded in email messages or linked to in order to drive traffic to a website or landing page.
Z
Zombie Email: An email address that is no longer active or in use, but is still included in mailing lists or databases and can cause delivery issues or damage to sender reputation. Zombie email addresses can occur due to typos, abandoned accounts, or fraudulent sign-ups.
Zero-click searches: A type of search engine results page (SERP) feature that displays information directly in the search results, without requiring the user to click through to a website. Zero-click searches can impact email open rates, as users may be satisfied with the information displayed in the search results and not click through to the email.
ZIP code targeting: A type of email segmentation that targets recipients based on their ZIP code or postal code. ZIP code targeting can be used to deliver localized content, promotions, or offers to recipients in specific geographic areas.
Zombie subscriber: A recipient on an email list who has not engaged with email messages for an extended period of time, but who has not formally unsubscribed from the list. Zombie subscribers can negatively impact email deliverability and engagement metrics, and should be removed from email lists through list hygiene practices.
Zero bounce rate: A measure of the percentage of email addresses in a mailing list that are valid and deliverable. A zero bounce rate indicates that every email address in the list is valid and that all emails sent to those addresses will be successfully delivered.
Zero inbox: A state in which a user has no unread or unprocessed emails in their inbox. Achieving a zero inbox requires regularly processing and organizing emails as they are received.
ZIP+4 code: A postal code system used in the United States that adds four digits to the end of a standard ZIP code to improve mail delivery accuracy. Including ZIP+4 codes in email marketing campaigns can improve deliverability by ensuring that emails are sent to the correct geographical location.
