Email Glossary

SPF

SPF (Sender Policy Framework) is a DNS record listing which mail servers may send email for your domain, so receivers can spot forgeries.

DKIM

DKIM (DomainKeys Identified Mail) adds a cryptographic signature to your email so the receiver can verify it wasn't altered and really came from your domain.

DMARC

DMARC tells receiving servers what to do with email that fails SPF or DKIM, and sends you reports — stopping others from spoofing your domain.

SMTP

SMTP (Simple Mail Transfer Protocol) is the standard protocol mail servers use to send and relay email across the internet.

IMAP

IMAP (Internet Message Access Protocol) lets an email client read and manage messages stored on a server, keeping them in sync across devices.

POP3

POP3 (Post Office Protocol) downloads email from a server to one device and usually removes it from the server — the older, simpler alternative to IMAP.

MX Record

An MX (Mail Exchange) record is a DNS entry that tells the internet which mail server receives email for your domain.

Catch-All Email

A catch-all email address accepts mail sent to any address at your domain, even ones that don't exist — handy for testing and avoiding lost mail.

Email Bounce

An email bounce is a message returned to the sender because it couldn't be delivered — a hard bounce is permanent, a soft bounce is temporary.

Transactional Email

A transactional email is an automated, one-to-one message triggered by a user action — a verification code, receipt, or password reset — not marketing.

Magic Link

A magic link is a one-time login URL sent by email that signs a user in when clicked — the password-free heart of passwordless authentication.

One-Time Password (OTP)

A one-time password (OTP) is a short code, valid once and briefly, sent by email or SMS (or generated by an app) to verify a user at signup or login.