Email Glossary
General Email Marketing Terms
Email Campaign: A coordinated set of email messages sent to achieve a specific goal
(e.g., promoting a product, nurturing leads).
Email List: A collection of email addresses gathered through subscriptions or sign-ups, forming your audience.
Segmentation: Dividing an email list into smaller, targeted groups based on criteria like behavior, location, or purchase history.
Personalization: Customizing email content using subscriber data (e.g., name or past purchases) to increase relevance and engagement.
Dynamic Content: Email content that changes based on subscriber data (like personalized product recommendations).
Email Automation: Setting up pre-scheduled or behavior-triggered emails (e.g., welcome sequences, abandoned cart emails).
Drip Campaign: A series of automated emails sent over time, guiding users through a sales funnel.
Re-Engagement Campaign: A targeted email strategy to win back inactive subscribers.
Transactional Email: Emails triggered by a user’s action (e.g., order confirmations, password resets).
Promotional Email: Marketing emails sent to promote products, services, or special offers.
Opt-In: The process of a user consenting to receive emails — can be Single Opt-In (one-step) or Double Opt-In (confirmation required).
Opt-Out (Unsubscribe): When a recipient chooses to stop receiving emails by clicking the unsubscribe link.
Subscription Form: A form on a website or landing page where users enter their email to join your list.
Preference Center: A page allowing subscribers to update their email preferences (like frequency or topics of interest).
Email Metrics & Performance
Open Rate: The percentage of recipients who opened your email — indicates subject line effectiveness.
Click-Through Rate (CTR): The percentage of email recipients who clicked a link inside the email — reflects engagement.
Click Rate: The number of clicks as a ratio of unique users who clicked against the number of emails delivered.
Conversion Rate: The percentage of recipients who took a desired action (e.g., purchase, sign-up) after clicking a link.
- Bounce Rate: The percentage of emails that couldn’t be delivered. It includes:
- Hard Bounce: Permanent delivery failure due to invalid email addresses.
- Soft Bounce: Temporary delivery failure due to full inboxes or server issues.
Unsubscribe Rate: The percentage of recipients who opted out of your email list.
Spam Rate: The percentage of recipients who reported your email as spam.
Deliverability: The ability of an email to reach the recipient’s inbox without being blocked or filtered into spam.
Inbox Placement Rate: The percentage of emails that reach the inbox (not spam or junk folders).
List Growth Rate: The rate at which an email list is expanding — new subscribers minus unsubscribes and bounces.
Engagement Rate: Combines open rates, click rates, and conversion rates — shows overall email interaction.
Email Content and Design
Subject Line: The clickable headline that recipients see in their inbox — crucial for open rates.
Preheader Text: The short summary text following the subject line in inboxes — acts as a teaser for the email content.
Call to Action (CTA): A button or link encouraging readers to take a specific action (e.g., “Buy Now,” “Learn More”).
Email Header: The code containing metadata like the sender, recipient, and subject — crucial for deliverability.
Email Body: The main content of your email, including text, images, and CTAs — optimized for design and responsiveness.
Email Footer: The bottom section of an email containing unsubscribe links, contact info, and legal disclaimers.
HTML Email: An email with images, colors, and fonts — more visually engaging than plain text emails.
Plain Text Email: A simple email without design elements — often used for personal or transactional messages.
Dynamic Tags (Merge Tags): Placeholder text that auto-populates subscriber info (like ‘Hi {{FirstName}}’) for personalization.
Email Testing and Optimization
A/B Testing: Sending two variations of an email to a small audience to see which one performs better before sending the winning version to the full list.
Seed Testing: Sending test emails to a ‘seed list’ to check deliverability and design before full deployment.
Render Testing: Checking how an email appears across different clients (Gmail, Outlook) and devices for consistent design.
Email Throttling: Sending emails in batches over time to avoid triggering spam filters.
Deliverability and Compliance
List Hygiene: The process of regularly cleaning an email list by removing invalid, inactive, or unengaged subscribers.
Feedback Loop (FBL): A service by mailbox providers like Yahoo and Outlook that notifies you when recipients mark your emails as spam.
Whitelist: A list of approved email addresses marked as trusted by recipients, ensuring emails go straight to their inbox.
Blacklist: A list of IP addresses blocked due to spam complaints or poor sending practices, preventing email delivery.
Greylisting: A method where servers temporarily delay emails from unknown senders — legitimate senders retry, while spammers often don’t.
Suppression List: A list of email addresses excluded from future campaigns, including unsubscribers and spam reporters.
CAN-SPAM Act: U.S. law setting rules for commercial email — covers transparency, opt-outs, and penalties.
GDPR (General Data Protection Regulation): European law governing data privacy, including consent rules for email marketing.
Technical Email Marketing Terms
ESP (Email Service Provider): A platform used to create, send, and track email campaigns (e.g., cmercury, Mailchimp, Brevo).
SMTP (Simple Mail Transfer Protocol): A protocol used to send emails between servers.
API (Application Programming Interface): Allows email platforms to integrate with other apps or websites for automation.
MTA (Mail Transfer Agent): Software that sends emails from the sender’s server to the recipient’s inbox.
IP Address: A unique number assigned to the server sending emails — crucial for tracking sender reputation.
- Dedicated IP: An IP address solely used by one sender — ideal for high-volume email marketing.
Shared IP: An IP address used by multiple senders — suitable for smaller senders.
Sender Reputation: A score assigned by ISPs based on email quality, affecting inbox placement.
SPF (Sender Policy Framework): An authentication method that verifies the sender’s IP is allowed to send on behalf of a domain.
DKIM (DomainKeys Identified Mail): Adds a digital signature to emails, ensuring they haven’t been altered during transit.
DMARC (Domain-based Message Authentication, Reporting & Conformance): An email authentication policy that prevents spoofing by aligning SPF and DKIM.
BIMI (Brand Indicators for Message Identification): Displays brand logos next to emails in supported inboxes for brand trust
JMRP (Junk Mail Reporting Program): A Microsoft service that notifies email senders when messages are reported as spam.
Web Beacon (Tracking Pixel): An invisible image embedded in emails to track opens and user activity.
UTM Parameters: Tags added to email links to track campaign performance in Google Analytics.
Analytics and Reporting Tools
Google Postmaster Tools: A free tool to monitor email reputation and deliverability for Gmail users.
List-Unsubscribe Header: A hidden feature in emails that allows recipients to easily unsubscribe with one click.
Precedence Header: A header used to classify automated emails (e.g., auto-replies or bulk mail) — helps ISPs identify email type.
Email Rendering: How an email appears across different email clients (Gmail, Outlook, Apple Mail) and devices.
Email Deliverability: The ability of your emails to reach recipients’ inboxes, affected by sender reputation and authentication.
Email Queue: A line-up of emails waiting to be processed and sent by the mail server — crucial for managing large sends.
Bounce Codes: Numeric codes explaining bounce reasons — usually:
- 5xx: Permanent errors (hard bounces)
- 4xx: Temporary errors (soft bounces)
SIS (Subscriber Identity Store): A database storing detailed subscriber data — key for hyper-personalization.