About

Get your email into the inbox, and keep it there.

SenderSignal builds inbox trust for new domains, protects the reputation you earn, and proves where your mail is actually landing. 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. Sometimes the cause is a blacklist listing. More often it is duller than that, and worse: a domain nobody has ever received mail from, so the filters simply do not trust it yet. Either way you find out late, after the campaign has shipped.

So SenderSignal does three jobs, and it needs all three to be useful.

Three jobs, one product

  • Build the trust. Inbox Boost. A new domain has no sending history, which is why perfectly legitimate mail lands in spam. Inbox Boost earns that history for you, and the only thing we ask for is the domain: we provision a dedicated sending server for it, generate SPF, DKIM and return-path, and write them into your DNS ourselves through a connected registrar. Then it ramps daily volume on a schedule, generates real engagement against what it sends, and pauses itself if your bounce rate climbs. No SMTP form, no records to paste, nothing to do daily.
  • Protect it. Blacklist monitoring. A ramp is worth nothing if a listing lands halfway through. We check your domains, subdomains and sending IPs against 45+ blacklist and reputation sources, from Spamhaus, Barracuda and SpamCop to commercial APIs like Google Safe Browsing and Cisco Talos, as often as every minute on the top plans. The moment something is listed we route a structured alert to Slack, email, or any HMAC-signed webhook your team already lives in.
  • Prove it. Inbox intelligence. Reputation scores are a proxy. The real question is which folder your mail reached, so we send to seed inboxes at six providers and report the answer per provider. Then content analysis reads the message that actually arrived and tells you which lines are working against you, because the fix for a reputation problem and the fix for a subject line are completely different.

A product of Info Science Labs

SenderSignal is built and operated by Info Science 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 minute, 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.
  • Automatic beats a checklist. Anything that depends on a human remembering to do it daily will eventually not get done. The ramp schedules itself, the rechecks run themselves, and the brakes are automatic.
  • 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 45+ 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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