Glossary Archive

A blocklist focused on domains associated with abusive traffic; can affect mail when the domain appears in sender identity or links.

A human-readable internet identifier (e.g., example.com) that maps to underlying DNS records and services.

Gradually increasing sending volume from a new or newly-changed domain to build a positive reputation with mailbox providers.

Denial-of-Service: an attempt to make a system unavailable by overwhelming it with traffic or requests (single-source or limited sources).

A subscription method where a new subscriber confirms via a follow-up email/link before being fully added to a list, improving list quality and consent proof.

The set of standards used to verify email legitimacy—primarily SPF, DKIM, and DMARC (including alignment and policy).

How recipients interact with email—opens (with tracking caveats), clicks, replies, conversions, and other actions indicating interest. Recipient interactions with email (positive or negative), such as opens (with tracking caveats), clicks, replies, unsubscribes, and spam complaints.

Keeping email lists clean and healthy by removing/suppressing invalid addresses, complainers, unsubscribes, and long-term inactive recipients.

A platform that sends email on behalf of customers and provides tools for lists, campaigns, automation, and reporting. ESPs send commercial or transactional email on behalf of organizations using dedicated infrastructure, analytics, and compliance controls.

Email Service Provider: a platform that enables bulk and automated email sending, list management, and reporting on behalf of organizations.