What Is an Email Blacklist?
Email blacklists (DNSBLs) are real-time databases of IP addresses known to send spam. Mail servers check incoming connections against these lists and may reject or flag messages from listed IPs. Being listed can severely impact your email deliverability.
What to Do If You're Blacklisted
- Identify the root cause — compromised server, open relay, or spam complaints
- Fix the underlying issue and secure your mail server
- Request delisting from each blacklist provider (most have automated processes)
- Set up SPF, DKIM, and DMARC records to improve sender reputation