BTC Black

Blocklist Threat Clearinghouse — Real-time DNS Blacklists

ESP Accounts RBL

esp.btcblack.it

Email Service Providers (ESPs) such as Mailchimp, Brevo, Sendgrid, and Amazon SES are frequently abused by spammers who register accounts specifically to send bulk unsolicited email. Because these campaigns originate from the ESP's own infrastructure, they often bypass traditional IP-based blacklists that would otherwise catch direct-to-MX spam.

This DNSBL lists hashed identifiers of ESP accounts confirmed to have been used for spam or abusive bulk email. It enables mail filters to flag or reject messages delivered via known-abusive ESP accounts, regardless of the sending IP address.

Key Features
DNS Query Example
$ host <hash-of-account>.provider.esp.btcblack.it
<hash-of-account>.provider.esp.btcblack.it has address 127.0.0.2

For more info send an email to info@btcblack.it.
The service is sponsored by SNB.