An email’s journey, secured in four stages
DeepFilter runs every incoming message through a multi-layered defense chain across four stages: pre-analysis, deep inspection, evaluation and decision. Every layer’s score combines into one trust score, and the reason behind every decision is transparent.
Four stages, one trust score
Dozens of signals combine into a single trust score; every decision is transparent.
Pre-Analysis
The sender and the message pass a first screening across authentication, blocklist and statistical classification layers within seconds.
Deep Inspection
AI, central intelligence, signature matching and visual inspection layers examine the message in depth.
Evaluation
Scores from every layer combine into one trust score; the mail is classified as clean, suspicious or dangerous.
Decision
Email that clears the trust threshold is delivered to the recipient; the rest is quarantined.
Not a single spam filter, a layered defense
SPF/DKIM authentication and scenario-based policy, blacklist queries, statistical classification, AI-assisted detection, similarity analysis, antivirus and phishing detection combine into one trust score across seven layers. Borderline mail is marked "suspicious".
DEEPFILTER_POLICY_RBL · Reputation / Blocklist+25
DEEPFILTER_POLICY_SPF_FAIL · Authentication+25
HARD_QUARANTINE_HELO_FAIL · Technical+25
DEEPFILTER_AI_SPAM · prob=0.9887 · AI+10
RBL_SPAMHAUS_XBL · Reputation / Blocklist+4
What happens to each message
The tools behind the four-stage chain; all running on your own server.
Authentication
SPF/DKIM verification with scenario-based policy; outbound DKIM signing.
Reputation / blacklists
RBL/DNSBL/URIBL queries with open-resolver false-positive protection.
AI + statistical
AI-assisted detection and statistical classification working together.
Similarity analysis
Body shingle and visual similarity match a message against known spam signatures.
Antivirus
ClamAV plus a centrally signed up-to-date feed; viruses stay quarantined.
Attachment control
Block executable/risky attachment types inbound and outbound.
Quarantine management
Admin filters/audit + end-user magic-link portal.
Delivery & routing
Domain-based routing, smarthost/relay, queue tracking and retry.
Explainable scoring
400+ rule knowledge base showing why each message scored.
See the defense chain on your own traffic
We set up a guided POC on your existing infrastructure and walk you through every stage.