Sender domain blocklist (Spamhaus DBL)
Reputation & Blocklists · Critical priority · hard-fail gate
What it is
Spamhaus DBL lists domains seen in spam/phishing/malware, even when sent from clean IPs.
How to fix it
If listed, identify why (compromise/abuse) and request delisting; never reuse burned domains.
This is a hard-fail gate. If it fails, Gmail / Yahoo / Outlook may junk or reject your mail regardless of everything else — so fix it first.
Check your email
See how your real email scores on this and every other deliverability factor.