Blacklist
A database identifying spam senders.
A blacklist is a list of IP addresses or domains flagged for sending spam or malicious emails. Being blacklisted means emails sent from these sources are likely to be blocked or sent to spam folders. Blacklists are managed by ISPs and anti-spam organizations. To avoid blacklisting, marketers must maintain list hygiene, avoid spammy language in email content, and follow compliance regulations like CAN-SPAM, GDPR, or CASL. Regularly monitoring sender reputation and authenticating emails with SPF, DKIM, and DMARC are critical steps to stay off blacklists.