EchoFetch Website Glossary
A glossary of all things pertaining to email.
A – D
ADA
Americans with Disabilities Act
The ADA is a federal civil rights law that prohibits discrimination against people with disabilities in everyday activities, such as visual, auditory, physical, speech, cognitive, language, learning, and neurological disabilities.
See ADA.gov for more information.
API
Application Programming Interface
An API is an application programming interface for two or more computer programs or components to communicate with each other. It is a type of software interface that offers a service to other pieces of software using requests and responses.
Alt-Text
Alternative Text
Alt-text is the text or copy encoded or embedded in a digital image and displays when hovering a mouse cursor over that image. Alt-text is also readable by assistive technologies.
Blacklist
A list of known spam sources.
A blacklist is a list of IP addresses that have been reported and listed as “known” sources of spam. Public blacklists are published and made available to the general public, which users across the globe can contribute to and use, either for free or as a paid service.
Block
A refusal to deliver an email from the sender.
A block is a mailbox provider or server's refusal to accept an email message for delivery. Many mailbox providers block emails using their IP address or domain using a public or private blacklist where they were reported to send spam or viruses. They can also be blocked for content that violates their email policy or spam filters.
Bounce
A failed delivery error message.
A bounce is an error message mailbox providers send back to the sending email server when an email send attempt fails delivery. This can be a permanent (Hard Bounce) or temporary (Soft Bounce) error.
CAN-Spam Act
Controlling the Assault of Non-Solicited Pornography and Marketing Act.
The CAN-Spam Act is a United States law establishing national standards for the sending of commercial e-mail and some text messages sent to wireless devices, including content on commercial websites.
See details at the Federal Trade Commission's website.
CASL
Canada’s Anti-Spam Legislation.
CASL reinforces best practices in email marketing and combat spam and related cyber threats. These threats include identity theft, phishing and the spread of malicious software, such as viruses, worms and trojans (malware).
See details at the Government of Canada's website.
CNAME
Canonical Name
CNAME records are DNS records that map an alias name or subdomain (www or blog) to a root domain name (echofetch.com). These records are often used to point services hosted on different IP addresses to a primary domain name.
CSS
Cascading Style Sheets
CSS is a style sheet language used for specifying or enhancing the presentation and styling of a document written in a markup language, such as HTML. It provides more control of the document’s presentation and styling, better website speed, and is easier to maintain than HTML alone.
DKIM
DomainKeys Identified Mail
DKIM is a protocol that authenticates every email with a cryptographic signature. DKIM signatures allow mailbox providers to associate an email with its sender and verify that the content of the email has not been changed during transmission.
DMARC
Domain-based Message Authentication, Reporting, and Conformance.
DMARC is an email authentication protocol that protects domain owners from unauthorized use. It tells a receiving email server what to do if neither SPF nor DKIM passes and provides a reporting mechanism for authentication failures.
DNS
Domain Name System
DNS provides translation services between human-readable domain names and machine-readable IP addresses. The most common analogy for DNS is that it serves as the phone book for the Internet.
Domain Name
Identification label for a website.
A domain name is an identification label to indicate ownership or control of internet resources, such as websites (echofetch.com), computers, networks, and services.
E – K
Email
Electronic Mail
Email, or e-mail, is a communication method of transmitting and receiving digital messages across computer networks such as a computer or smartphone.
Email Accessibility
An email that is created for everyone’s user experience.
Email accessibility is the practice of writing, designing, and coding HTML emails that people can easily understand and engage with, regardless of visual, physical, cognitive, or neurological disabilities.
See our guide to make your emails more accessible.
Email Authentication
SPF, DKIM, and DMARC
Email authentication is the process of verifying the digital identity of the sender of a communication. In email marketing, the most widely used and accepted forms of email authentication are SPF, DKIM, and DMARC.
Email Client
Software or webmail
An email client is a program a user interacts with to read and send email messages. Email clients can be software applications on your desktop or smartphone, like Outlook Express, Thunderbird, and Lotus Notes, or webmail services like Yahoo, Hotmail, and Gmail.
ESP
Email Service Provider
An ESP is a company that sends emails on behalf of its clients. It may also provide other email-related services like list management, deliverability monitoring, and performance reporting, such as Mailchimp, Mailgun, Constant Contact, etc.
FBL
Feedback Loop
Feedback loops allow senders to receive alerts from mailbox providers when a subscriber complains. The mailbox provider forwards the complaints from their users to the sender's organization, primarily so the sender can suppress this user in their database. Senders can see their compliance status with some mailbox providers, such as Google Postmaster Tools, or Yahoo Sender Hub, etc.
GDPR
General Data Protection Regulation
The GDPR is a European law that protects the privacy and security of personal data and applies to the collection and use of personal information by organizations in the European Economic Area (EEA) and certain non-EEA organizations that process EEA data. It is toughest privacy and security law in the world.
See details on the Information Commissioner's Office website.
Hard Bounce
A permanent failed delivery error message.
A hard bounce is an error classification sent from a mailbox provider to the sender when an email sender attempts to send an email, and it fails delivery. The bounce can be from an invalid or unknown email address or the recipient has blocked the sender. This is a permanent error; this email address should be removed immediately.
HTML
Hypertext Markup Language
HTML is the standard markup language for documents designed to be displayed in a web browser or email. Most emails are either text-only or HTML to include graphics, layout, decorative links, and color.
IMAP
Internet Message Access Protocol
IMAP is a protocol allowing an email client to access email on a remote mail server. This allows users to access their email from any device, such as a phone, laptop, or tablet, without downloading it.
Inactive Subscribers
Subscribers who haven’t interacted with your emails.
Inactive subscribers, or “non-responders,” are email recipients who have not taken action on your emails (opens, clicks) within a certain amount of time.
Infrastructure
Physical Servers
Infrastructure refers to the hardware used to deploy emails or have an email service provider deploy them on your behalf. The hardware is commonly referred to as your mailing transport agent (MTA).
IP Address
Internet Protocol Address
An IP address is a unique number assigned to each device connected to the internet and can be dedicated or shared.
A dedicated IP address allows the sender complete control of emails sent from their IP address and the resulting reputation.
A shared IP address means other senders are mailing campaigns utilizing the same IP address.
ISP
Internet Service Provider
An ISP is a company that provides individuals and organizations access to the internet and other related services.
L – O
List Hygiene
Subscriber list maintenance
An ISP is a company that provides individuals and organizations access to the Internet and other related services.
List-Unsubscribe
A mechanism allowing users to remove themselves from an email list.
The list-unsubscribe header is an email header that provides instructions for a brand's unsubscribe process. Mailbox providers can then display an unsubscribe button for recipients to click on if they would like to stop future messages automatically.
MIME
Multipurpose Internet Mail Extensions
MIME is an internet standard that allows the exchange of various data files via email, including audio, video, images, and application programs.
MTA
Message Transfer Agent
MTA is email server software that receives and relays emails from one computer to another using the Simple Mail Transfer Protocol (SMTP).
MUA
Mail User Agent
MUA is email client interface software that allows users to access, create, format, and send email messages.
P – S
POP3
Post Office Protocol 3
POP3 is an application-layer Internet standard protocol used by e-mail clients to retrieve e-mail from a mail server. Along with IMAP, it is one of the most common protocols for email retrieval.
Pristine Spam Trap
An email address created solely to catch spammers.
Pristine spam traps, or “honeypots,” are email addresses created exclusively to capture spammers. An actual human never owns these email addresses, does not subscribe to email programs, and does not make purchases. Many spam trap operators will post (seed) pristine traps across the internet on various participating websites. They are usually hidden in the webpages' background code and acquired by spambots when scraping email addresses.
Recycled Spam Trap
An old email address that was reused or recycled to catch spammers.
Recycled spam traps are email addresses that a real person once used. These email addresses are abandoned accounts that mailbox providers recycle as spam traps. Before turning an abandoned email address into a spam trap, mailbox providers will return unknown user error codes for a year. Once a mailbox provider reactivates (recycles) the abandoned email address, mail is again allowed to be received by the email address. If you’re hitting recycled spam traps, this typically indicates a problem with your data hygiene.
Sender Reputation
The reputation score of your email domain and IP address.
Sender reputation, or email reputation, determines the validity of an incoming sender by analyzing past sending behaviors. Mailbox providers evaluate this metric when deciding whether to deliver an incoming email to the inbox or the spam folder.
SEO
Search Engine Optimization
SEO is the process of getting traffic from free, organic, editorial, or natural search results in search engines.
Spam
Unwanted, unsolicited messages sent in bulk by email.
Spam is an email message you did not ask for and do not want from somebody you do not know who wants to sell you something, such as a product or a service.
SPF
Sender Policy Framework
SPF records allow a sender to specify the list of IPs allowed to send mail for that domain and allow ESPs to reject messages originating from IPs not listed in the domain's SPF record.
SERP
Search Engine Results Pages
An SERP is a page that appears after a user enters a query into a search engine. The page displays a list of relevant results to the query, including organic pages and sponsored ads.
SMPT
Simple Mail Transfer Protocol
SMTP is an Internet standard communication protocol or application mail servers use to send, receive, and relay outgoing emails between senders and receivers.
Soft Bounce
An often temporary failed delivery error message.
A soft bounce is an error classification received from a mailbox provider when an email send attempt fails to deliver to a real email address. This is often a temporary error caused by several possible factors, such as the user’s mailbox being full or the mailbox provider receiving too many emails at once. These emails can be sent again at a different date and/or time.
Depending on the error message, best practice is to remove this subscriber after 3 - 5 soft bounces.
T – Z
TCP/IP
Transmission Control Protocol/Internet Protocol
TCP/IP is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria.
Throttling
A timely limit on the number of outbound emails sends.
The practice of regulating how many email messages a sender deploys to one mailbox provider or mail server at a time. Some mailbox providers bounce emails if they receive too many messages.
Unknown User
The email address is invalid.
An unknown user is a hard bounce error code generated by a mailbox provider when an email address is not registered in its system.
UTM
Urchin Traffic Monitor
UTM parameters are short snippets of code added to the end of a URL to help you track information about where someone came from—the referring domain—and what they clicked on to get there.
Whitelist
A list of reputable email addresses allowed to bypass reputation and spam scans.
The opposite of a blacklist, a whitelist is a record of senders who meet established standards for reputation, engagement, and sending practices, thus proving themselves to be legitimate and responsible senders.