About

We watch your sender, so you can ship.

SenderSignal is a real-time deliverability and reputation monitoring platform built for the teams who depend on email to run their business.

Why we built it

Every sending team eventually gets the same call: a customer says the email never arrived. By the time you trace it back to a blacklist listing, the campaign has already shipped, deals have stalled, and your reputation needs days to climb back. SenderSignal exists so that call never happens again.

We check your domains, subdomains, and sending IPs against 48 blacklist and reputation sources, from Spamhaus, Barracuda, and SpamCop to commercial APIs like Google Safe Browsing and Cisco Talos, on a schedule as fast as every 15 minutes. The moment something is listed, we route a structured alert to Slack, email, or any HMAC-signed webhook your team already lives in.

A product of Infoscience Labs

SenderSignal is built and operated by Infoscience Labs . A small, focused engineering shop building infrastructure tools for teams who care about deliverability, observability, and the boring-but-critical plumbing that keeps modern software running. We're backed by years of experience operating high-volume sending infrastructure at scale.

What we believe

  • Speed matters. A listing caught within the hour versus discovered six days later is the difference between a successful campaign and a lost quarter. Rechecks run as fast as every 15 minutes, and alerts fire the moment a listing is confirmed.
  • Signal over noise. We don't notify you about false positives. We don't flap. When SenderSignal pages your on-call, it's real.
  • Route anywhere. Every alert is routable. If your stack speaks JSON or HTTP, we deliver to it with HMAC-SHA256-signed webhook payloads you can verify end to end.
  • Zero touch on your sending. We never proxy, throttle, or interfere with your mail flow. We observe public reputation feeds, DNS blocklists, and DNS authentication records. Your MTAs, ESPs, and SMTP relays stay untouched.

Coverage

Every monitored asset is checked against a curated catalog of 48 blacklist and reputation sources: 34 IP blocklists, 9 domain and URI lists, 5 lists covering both, and 6 commercial reputation APIs. Beyond blacklists, we watch SPF, DKIM, DMARC, MTA-STS, BIMI, TLS certificates, MX changes, and reverse DNS, and pull Gmail's own view of your reputation through Google Postmaster Tools.

Get in touch

Have a question, a security disclosure, or want to talk about an enterprise deployment? We'd love to hear from you.

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