• Ad Exchange

    An Ad Exchange is a digital marketplace where advertisers and publishers can buy and sell display, video, and mobile advertising.

  • Ad Impression

    An Ad Impression occurs when an advertisement is displayed on a web page.

  • Ad Unit

    An Ad Unit is the web page container that holds the advertising copy and graphics for a digital advertisement.

  • Affiliate Marketing

    Affiliate Marketing is an activity in which companies offer to pay individuals or other businesses — the ‘affiliates’ — to promote their products or services, usually in return for a commission on any sales made.

  • Affirmative Consent

    Affirmative consent is the knowing, explicit opt-in by a recipient to receive email.

  • Allow List

    An Allow List is a set of email or IP addresses that have been granted access to to a service, or a list of web sites that a user is permitted to access.

  • Automated Email

    Automated Email allows you to dynamically send relevant content to individual recipients.

  • Autoresponder

    Autoresponders generate email responses to actions and events.
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  • Bayesian Filter

    Bayesian Filtering is a technique for detecting spam.

  • Blocks

    Blocked emails happen when your IP address has been added to a deny list or has been blocked by an ISP or messaging organization.
  • Bounces

    Bounced emails are emails that are returned to the server that sent them.

  • Bulk Email Service

    Bulk email service is a way to send an email, or multiple emails, to a large list of various recipients.
  • Bulk Mail Folder

    Bulk Mail folder is also called “spam” or “junk” folder, the folder where questionable email is routed.
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  • Campaigns

    Campaigns are used to send custom emails to targeted recipient segments.

    The CAN-SPAM Act lists the guidelines, requirements, and penalties regarding the sending of commercial bulk email.
  • Categories

    Paying attention to your deliverability metrics can help optimize your delivery rate and reduce the risk of being seen as a spammer.
  • Challenge Response

    An automated reply to a sender to filter out spammers.
  • Clicks and Unique Clicks

    Track the links your customers click from your emails with SendGrid.

  • Click-Through Rate (CTR)

    What is CTR?


    The CNAME record creates an alias for subdomain.yourdomain.com and points it to another domain
  • Complaint

    When an email recipient identifies an email message as spam or junk by clicking the “report spam” or “mark as junk” button within their email reader.

  • Custom Fields

    Custom fields allow you add extra information about your contacts to your contact database.
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  • Deferral

    A deferred status can occur when an ISP or mailbox provider is for some reason not ready to accept email from your IP address.
  • Deliverability

    Email deliverability is a critical component for all email communication with customers. Strong deliverability is a necessity for any web application.
  • Delivery

    A delivery is recorded when a request to send an email results in the delivery of that email to the end recipient.
  • Demand-Side Platform (DSP)

    Definition of a Demand-Side Platform (DSP)
  • Deny list

    A list of IP addresses that are known to send unsolicited or unwanted emails.

  • Direct Response Advertising

    Definition of Direct Response Advertising
  • DKIM

    DKIM is an email authentication protocol that helps ISPs better identify legitimate email senders.


    Domain-based Message Authentication, Reporting and Conformance (DMARC) is a standard for determining the authenticity of the person or service sending email on behalf of a domain.

  • DNS

    Domain Name System (DNS) translates a domain name into an IP address to find the owner’s site.

  • Domain

    A named internet address that resolves to an IP address
  • Domain authentication

    Domain authentication shows email providers that SendGrid has your permission to send emails on your behalf.
  • Drip Campaign

    Drip Campaigns are a type of automated email marketing strategy.

  • Drops

    In certain cases, SendGrid will “Drop” a message to a specific email address in order to protect your sender reputation. SendGrid keeps Email Lists to track bounces, spam reports, and unsubscribes for each of our users.

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  • Email API Integration

    Email API integration allows senders to easily sync their email service provider with their platform and software tools to automate key functions
  • Email Authentication

    Technical standards to help ISPs and other receivers validate the identity of an email sender.

  • Email Harvesting

    Email harvesting is the process of obtaining lists, either by purchase or theft, of valid email addresses for the purpose of sending bulk email or spam
  • Email Marketing

    Email Marketing represent the email communications sent to promote a commercial product or service.

  • Email Service Provider

    An email service provider provides transactional and marketing email services.

  • Event Webhook

    Event Webhooks provides data about the email you send when the user takes an action.

  • Expandable Banner

    Definition of an Expandable Banner
  • Expired

    Bounced - Expired emails are emails that are unable to be delivered within 72 hours.

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  • General Data Protection Regulation (GDPR)

    The General Data Protection Regulation (GDPR) of the European Union (EU) is a law that regulates the handling of personal data and outlines the rights individuals have with regard to their data.
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  • Header

    An email header is the information that tells email recipients and servers where the email has come from and where it should go.
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  • IMAP

    IMAP is a protocol many applications use to retrieve mail from your mail server
  • Invalid Email

    occurs when you attempt to send email to an address that is formatted in a manner that does not meet internet email format standards.
  • IP Address

    A unique numerical address that defines an internet location.
  • IP Warmup

    Initially splitting up the email send requests from a new dedicated IP, so it doesn't get blocked.

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  • Link branding

    Email link branding allows all of the click-tracked links and opens tracked images in your emails to be from your domain instead of from sendgrid.net.
  • Lists

    Lists are simply static collections of Marketing Campaigns contacts.
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  • Mailbox Provider

    An email service provider provides transactional and marketing email services.

  • Mail Merge

    Mail Merge is a process to create customize emails from a generic form or template.

  • MTA

    MTA stands for Mail Transfer Agent. It is software that transfers electronic mail messages from one computer to another using a client–server application architecture.

  • MX Record

    An Mail Exchanger Record specified the mail server responsible for accepting email on behalf of a domain

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  • Open Rate

    The rate in which your customers open emails you've sent to them.
  • Open Relay

    An SMTP server configured in such a way that it allows anyone on the Internet to send email through it.

  • Opens & Unique Opens

    Track how many times your emails are opened with SendGrid
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  • Peer-initiated Invitations Campaign

    Peer-initiated Invitations are a Marketing Email campaign where you get customers to invite their friends and family. There are some caveats to consider about this marketing method.

  • Phishing

    A technique for acquiring information such as user names, passwords, credit cards, social security numbers and other personal data by masquerading as a trusted business.
  • Preheader

    A preheader is the short summary text that follows the subject line when an email is viewed in the inbox. Many mobile, desktop, and web email clients provide them to tip you off on what the email contains before you open it.
  • Programmatic Media Buying

    Definition of Programmatic Media Buying
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  • Rate Limiting

    Rate limiting happens when a recipient mail server doesn't allow emails to be delivered at the same rate as they were sent.

  • Reconfirmation Email Campaigns

    A reconfirmation email, otherwise known as a re-opt in email, reminds clients you correspond with about your business.

  • Reputation Monitoring

    The reputation score is based on your bounces, blocks, spam, invalid emails, and successfully delivered emails.

  • Request

    A request is recorded every time an application attempts to send an email through SendGrid's servers.
  • Reseller Email Account

    Some companies may resell SendGrid's services by having a formal Reseller Partnership with SendGrid.
  • Reserved Fields

    Reserved fields are those custom fields that cannot be deleted and do not count towards your allotment of 500 custom fields. They include fields such as email, first_name, and last_name in Marketing Campaigns.

  • Reverse DNS

    Reverse DNS is a method of resolving an IP address into a domain name.
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  • Scheduled Emails

    Scheduling emails allows the ability to have the email send process to begin at a certain time
  • Segmentation

    The practice of separating different types of email traffic.

  • Segments

    Segments are dynamic collections of Marketing Campaigns contacts grouped together, or segmented, based on the criteria you define.
  • Sender authentication

    Sender authentication refers to the process of showing email providers that SendGrid has your permission to send emails on your behalf.
  • Sender ID

    Sender ID is an email authentication standard developed by Microsoft that compares the email sender’s “From” address to the IP address to verify that it is authorized to send email from that domain.
  • Sender Identification

    A clear and accurate representation of the sender and purpose for email sent via Twilio SendGrid.

  • Senders

    Senders in Marketing Campaigns provide identity information about where the emails are coming from for their recipients in campaigns in order to ensure all CAN-SPAM regulations are followed.
  • SendGrid Message ID

    The SendGrid Message ID is a unique identifier generated and assigned by SendGrid for event identification purposes.
  • Sends

    Sends relate to your requests to deliver email to your recipients through SendGrid's API or UI, which you can schedule or retrieve aggregate data from.
  • Single Send

    A Single Send is a one-time email used to communicate a variety of nonautomated messages.

  • SMTP

    SMTP is an acronym for Simple Mail Transfer Protocol. SMTP is a process and set of guidelines for sending email.


    SMTP API is an API that allows you to tag your emails and provide customized email handling instructions on a per email basis.

  • SMTP Provider

    An email SMTP provider helps deliver large amounts of email from your server to the recipient’s server.

  • SMTP Relay

    An SMTP relay is used to send email between SMTP servers, when the servers are located on different domains.
  • SMTP Server

    SMTP server (Simple Mail Transfer Protocol) is an applications used to send email and react to response codes from receiving servers.
  • SMTP Service

    An SMTP service ensures delivery of your email at scale.

  • Spam

    The most simple way to define spam in the Email world is by using these 2 words unwanted email.

  • Spam Filter

    Software based email filters that look for spam and block it from going to the inbox.

  • Spam Reports

    Spam Reports are triggered when a customer marks a message as spam in their email client.

  • Spam Traps

    Spam traps, also called “honeypots”, are email addresses created (or re-activated) by ISPs specifically to lure spammers. In many cases, the only way to acquire the address is through an automated email address harvesting process.

  • SPF

    SPF is an email authentication standard that helps ISPs better identify legitimate email senders.
  • Spoofing

    Spoofing is a technique where forged email addresses are used to trick recipients into opening an email because the source has been hidden

  • Subscriber List Management

    Managing your subscriber list is key to keeping your subscribers happy.

  • Suspicious Sender

    A suspicious sender is a sender who sends email to recipients who have not given them express permission to do so.

  • System Fields

    System fields are available in the campaign builder that allow you to insert specific content into your campaign, such as web links, unsubscribe links, or links to your campaign's subscription preferences page. These system substitution tags are not related to your contact data and should not be confused with reserved or custom fields.

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  • Teammates

    Manage multiple users on one SendGrid account.
  • Throttling

    Learn more about deferrals and throttling
  • Timezones

    Local time, based on your current geographic location on the earth.
  • Transactional Email

    Transactional Emails represent the emails which are triggered by a user interacting with a web application.

  • Transactional Email Templates

    Transactional email templates are pre-coded email layouts that anyone can use to easily create and send transactional emails.

  • Transport Layer Security

    Protect transmission of email information with TLS and SendGrid

  • Triggered Actions

    Triggered Actions are initiated by a triggering event.

  • Triggered Email

    Triggered emails are another name for automated emails that are triggered by specific events or actions.

  • Trusted Sender

    A trusted sender is a sender who only sends email to those recipients who have given them express permission to do so.

  • Two Factor Authentication

    Multi-factor Authentication requires the user to have some information that only they could have to log into an account.
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  • Undelivered Email

    Email can be undelivered for various reasons, including an issue with email address or content.

  • Unknown User

    Bounced - Unknown User is an error indicating the email address does not exist.

  • UTM Parameters

    Defintion of UTM Parameters
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  • Web API

    Web API allows web servers and web browsers to easily interface with each other to enable account and data collection for services such as email.

  • Whitelabel

    Refers to the process of showing ISPs that SendGrid has your permission to send emails on your behalf.
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  • X-Message-ID

    The X-Message-ID is a header returned when sending email from SendGrid.

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