Glossary Archive

A DNS record that aliases one hostname to another. Commonly used for branded tracking subdomains; only one CNAME can exist for a given hostname.

A DNS record that aliases one hostname to another. Often used for branded tracking domains (link tracking, image hosting) and flexible DNS setups.

A low/unknown sending reputation state for a new or long-idle domain/IP, often requiring gradual warm-up to avoid filtering.

A recipient marking an email as spam/junk. Complaints harm sender reputation and should trigger suppression of that recipient.

The rate of recipients marking mail as spam/junk, commonly measured as unique complaints ÷ delivered (definition varies by mailbox provider).

A transactional email that asks a new subscriber to confirm their signup (typically via a confirmation link), enabling double opt-in.

A recipient’s explicit permission to receive messages from an organization, typically captured via an opt-in process (written or verbal, depending on policy/law).

Validating contact data (especially email addresses) before sending. Reduces bounces and protects sender reputation.

Completion of a desired action (e.g., purchase, signup, upgrade) attributable to a campaign or message.

A look-alike domain with no technical relationship to the legitimate brand domain (e.g., google.com vs googlewebsite.com).