A blacklisted domain or IP quietly breaks email delivery, erodes customer trust and signals a possible compromise. QSECS checks your domains and IP ranges against the major reputation and blacklist databases, then helps you understand and resolve any listing.
We assess how the wider internet sees your infrastructure, and why.
A blacklisting is often the first outward sign that something is wrong inside. Reputation providers, mail systems and browsers flag domains and IPs associated with spam, malware or abuse — and a listing can break email delivery and customer trust overnight.
QSECS checks your domains and IP ranges against the major reputation and blacklist databases, traces why any listing occurred, and guides both the cleanup and the delisting so the problem doesn't simply recur.
Domain and IP presence across major DNSBL, spam and abuse blacklists
Email-sender reputation affecting inbox placement and deliverability
Malware and phishing flags raised by browser and search-engine safe-browsing services
Shared-hosting and neighbouring-IP reputation that can taint your own
Root-cause indicators — open relays, compromised accounts or abused infrastructure behind a listing
Reputation Damage Outlasts the Deadline
A domain or IP can be blacklisted the moment attackers exploit a weakness you did not know you had — and quantum-era cryptographic failures will only widen that window. Executive Order 14412, "Securing the Nation Against Advanced Cryptographic Attacks," obliges federal systems to adopt post-quantum cryptography by hard deadlines: key establishment by December 31, 2030 and digital signatures by December 31, 2031. Catching the compromise that gets you blocklisted requires watching continuously, not checking once a quarter. QRedSentinel monitors your reputation continuously, so you hear about a compromise from us — not from a customer who can no longer reach you.
We don't just report a listing — we trace why it happened and help you get delisted and stay clean.
We enumerate every listing across reputation providers and explain its real-world impact
We investigate the underlying cause, distinguishing misconfiguration from active compromise
We guide remediation — authentication records, hygiene fixes and compromise cleanup — before delisting
We support delisting requests with the evidence providers expect to see
We advise on monitoring so a recurrence is caught early, not by your customers