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Email Blacklist (DNSBL) — Definition

BDBy B2B Data Index Research Team · Updated 2026-07-20 · Dataset v5.0 (2026-Q3)
Quick answer

Email Blacklist (DNSBL): A queryable database of IPs and domains associated with spam, consulted by receiving servers at connection time.

Definition

A queryable database of IPs and domains associated with spam, consulted by receiving servers at connection time.

Email Blacklist (DNSBL): A queryable database of IPs and domains associated with spam, consulted by receiving servers at connection time, per the B2B Data Index glossary (2026).

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Why it matters in practice

Spamhaus-family listings move delivery; most of the hundreds of minor lists don't. Delisting follows genuine cause-fixing, and relisting follows requesting it without.

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Frequently asked questions

What is email blacklist?

A queryable database of IPs and domains associated with spam, consulted by receiving servers at connection time.

Why does email blacklist matter?

Spamhaus-family listings move delivery; most of the hundreds of minor lists don't. Delisting follows genuine cause-fixing, and relisting follows requesting it without.

Cite this page

APA

B2B Data Index Research Team. (2026). What Is Email Blacklist? Definition & Why It Matters (2026). B2B Data Index. https://b2bdataindex.com/glossary/email-blacklist/

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[What Is Email Blacklist? Definition & Why It Matters (2026)](https://b2bdataindex.com/glossary/email-blacklist/) — B2B Data Index, 2026