Email terms, explained simply

A plain-English glossary of email terms you might encounter when managing business email.

Email has its own vocabulary. This glossary explains the terms you're likely to encounter when setting up, managing, or troubleshooting business email — in plain language, no jargon.

Quick summary

Use this page as a reference when you encounter an unfamiliar email term. Terms are listed alphabetically. Click any linked term to read a full guide on that topic.

Alias

An extra email address that delivers to an existing inbox. For example, info@yourbusiness.com can be an alias for jane@yourbusiness.com. See Email aliases & forwarding explained.

Attachment

A file (document, image, PDF, etc.) added to an email and sent along with the message body.

Auto-reply

An automatic response sent to people who email you, usually when you're out of the office. See Out-of-office & auto-replies.

Blacklist / Blocklist

A list maintained by spam-fighting organizations of domains or IP addresses known to send spam. If your domain is listed, your emails may be blocked. See Why your emails land in spam.

When an email cannot be delivered and is returned to the sender. A hard bounce means the address doesn't exist. A soft bounce means a temporary problem (the recipient's inbox is full, for example).

Sending a copy of an email to someone without other recipients knowing. BCC recipients can see the email but are hidden from everyone else on the thread.

CC (Carbon Copy)

Sending a visible copy of an email to additional recipients. Everyone on the email can see who is CC'd.

Catch-all

A setting that delivers any email sent to a non-existent address on your domain to a designated inbox. For example, a message addressed to inof@yourbusiness.com would still arrive. It only covers your own domain — a typo in the domain name itself sends the email somewhere else entirely. See Email routing & catch-all.

CNAME

A type of DNS record. Not directly an email record, but sometimes used in DKIM setup.

DKIM (DomainKeys Identified Mail)

A digital signature added to your outgoing emails. Receiving servers use a public key published in your DNS to check the signature, which confirms the message really came from your domain and wasn't altered on the way. One of the three authentication records. See SPF, DKIM & DMARC explained.

DMARC (Domain-based Message Authentication, Reporting & Conformance)

A policy record that tells receiving servers what to do with email that doesn't pass authentication. A message passes DMARC when either SPF or DKIM passes and the domain that passed matches the domain in the From address — so failing just one of the two isn't enough to trigger the policy. See SPF, DKIM & DMARC explained.

Domain

The part of an email address after the @ sign — e.g., yourbusiness.com. See What is a domain name?.

Draft

An email you've started writing but haven't sent yet. Drafts are saved automatically and can be returned to.

Distribution list

A single email address that delivers to multiple people at once. See Group & distribution lists explained.

Email client

The app or software you use to read and write email. Examples: Gmail (in a browser), Outlook, Apple Mail.

Email platform

The service that stores and manages your email. Examples: Google Workspace, Microsoft 365.

Email server

The computer that stores, sends, or receives emails. Also called a mail server.

Encryption (in transit)

Scrambling email data while it moves between servers so third parties can't intercept it. Most modern email platforms use TLS encryption for email in transit.

Filter / Rule

An automatic instruction you set in your email client to organize incoming messages. Example: "Move all emails from this sender to the Suppliers folder."

Folder

A way to organize email in your inbox. In Gmail, folders are called Labels.

Forwarding

Automatically sending a copy of incoming email to a different address. See Email aliases & forwarding explained.

Gmail

Google's email service. When used with your own domain on Google Workspace, it's Google's professional email platform.

Google Workspace

Google's paid suite of business tools, including Gmail with a custom domain, Drive, Calendar, and more. Formerly known as G Suite. See What is Google Workspace?.

Hard bounce

A permanent delivery failure — the email address doesn't exist or the domain is not configured for email. See Bounce.

Hidden metadata attached to every email: who sent it, when, what servers it passed through, and authentication results. Useful for diagnosing deliverability problems.

IMAP (Internet Message Access Protocol)

A protocol for receiving email that keeps messages on the server and syncs them across all your devices. This is what you should use. Contrast with POP3. See Setting up email in a desktop app.

Inbox

The folder where new emails arrive by default.

IP address

A numerical address for a computer on the internet. Mail servers have IP addresses; sender reputation is partly tied to the IP addresses a mail server uses.

Junk folder

Another name for the spam folder. Emails your provider suspects are unwanted are moved here automatically.

Label

Gmail's name for what other email clients call a folder. Labels can be added to emails and can overlap (an email can have multiple labels).

Mail server

The server that sends or receives email on behalf of a domain. See Email server.

Mailbox

Your personal email inbox. The storage space for all your email.

Marketing email

Email sent to a list of subscribers to promote a product, service, or content. The anti-spam rules in the US, the UK and Canada all require a clear way to opt out. Contrast with transactional email. See Transactional vs marketing email.

Microsoft 365

Microsoft's paid suite of business tools including Outlook, Word, Excel, Teams, and more. See What is Microsoft 365?.

MX record (Mail Exchange record)

A DNS record that tells the internet which server handles email for your domain. See DNS records explained.

Out-of-office reply

An automatic reply sent to people who email you while you're unavailable. See Out-of-office & auto-replies.

Outlook

Microsoft's email client. Available as a web app, desktop app, and mobile app.

Phishing

A type of scam where attackers send emails pretending to be a trusted source to steal credentials or money. See How to recognize a phishing email.

POP3 (Post Office Protocol version 3)

An older protocol for receiving email that downloads messages to one device and may delete them from the server. Avoid in favor of IMAP.

Primary domain

The main domain name used for your email — e.g., yourbusiness.com. You can have alias domains too.

Quota

Your storage limit — how much email and attachments you can hold on the server before you run out of space. See Email storage & archiving.

Reply-all

Sending a reply to every person in the original email thread, not just the sender.

Reputation (sender)

A score associated with your email domain and sending IP, based on your sending history. Good reputation = better deliverability.

Sender reputation

How trustworthy mail servers consider your domain and IP to be, based on sending history. See Why your emails land in spam.

Shared mailbox

An inbox that multiple team members can access using their own individual logins. See Shared mailboxes explained.

Signature

Text or formatting automatically added to the bottom of your outgoing emails — typically your name, title, company, and contact details. See Creating a professional email signature.

SMTP (Simple Mail Transfer Protocol)

The protocol used to send email from one server to another. See What is SMTP?.

Soft bounce

A temporary delivery failure — the recipient's mailbox is full or the server is temporarily unavailable. See Bounce.

Spam

Unsolicited, unwanted email. Also the folder where suspected spam is sent.

Spam filter

Automated software that analyzes incoming email and separates suspected spam from legitimate messages.

SPF (Sender Policy Framework)

A DNS record that lists which mail servers are authorized to send email from your domain. See SPF, DKIM & DMARC explained.

Thread

A chain of related emails — an original message and all the replies to it — displayed together.

TLS (Transport Layer Security)

Encryption used to protect email as it travels between mail servers.

Transactional email

Automated email triggered by a specific user action — an order confirmation, password reset, or booking notification. Contrast with marketing email. See Transactional vs marketing email.

Two-factor authentication (2FA)

A security method requiring a second form of verification (like a code sent to your phone) in addition to your password. See Email security basics.

Unsubscribe

Opting out of a mailing list. In the US, the CAN-SPAM Act requires a marketing email to explain clearly how the recipient can opt out, and many other countries have comparable rules. Gmail goes further for high-volume senders: anyone sending more than 5,000 messages a day to personal Gmail accounts must make their marketing and subscribed messages support one-click unsubscribe and carry a clearly visible unsubscribe link. This is general information, not legal advice.

Webmail

Accessing your email through a web browser, without installing an app. See Accessing email on the web.

Need a hand?

If you're stuck, email support@chykalophia.com and we'll help. Include your website address and a screenshot if you can.

Email terms, explained simply

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