Email Address Checker Scam, fraud, and blacklist lookup for any address
Got a suspicious email? Check the sender before you reply, click, or pay. isMalicious matches the address against scam blacklists, inspects its domain, and hands back a verdict with the evidence — free, no signup.
curl -d "email=you@example.com" https://ismalicious.com/api/keys/instant500 free requests/month · instant API key · no signup form
Scam
Blacklist Match
Domain
Sender Analysis
Disposable
Provider Detection
Bulk
API Screening
Key features. Everything you need to protect your infrastructure and users.
Scam Blacklist Matching
The address is checked against curated scam and fraud blacklists built from abuse reports and threat feeds.
Sender Domain Intelligence
The domain behind the address gets the full treatment: reputation, age, registration patterns, and listing history.
Disposable Address Detection
Known temporary and throwaway providers are flagged — the standard cover for fake accounts and one-shot fraud.
Paste the Whole Message
Smart lookup extracts every indicator from a pasted email — sender, links, phone numbers, wallets — and checks them together.
API-First Workflow
Screen addresses at signup, in CRM imports, or inside fraud pipelines with the same verdict over REST.
Evidence, Not Just a Score
Every verdict names its sources, so an analyst can defend the decision instead of trusting a black box.
Use cases. How security teams use this tool.
Suspicious Sender Triage
Check the sender of an unexpected invoice, job offer, or support message before engaging.
Signup Fraud Screening
Flag disposable and blacklisted addresses at registration, before they cost you.
BEC and Phishing Response
Enrich reported phishing emails with sender reputation and related infrastructure.
Marketplace Trust and Safety
Screen counterparty addresses in transactions and listings.
How to tell if an email address is a scam
Three signals separate most scam addresses from legitimate ones: the address or its domain already appears in abuse reports; the domain is days old or registered through patterns common to fraud campaigns; or the provider is a disposable service built for throwaway accounts. An email checker automates all three lookups in one pass and returns the evidence, so you are not judging on gut feeling.
Email reputation vs. email verification
Email verification asks whether an address can receive mail — a deliverability question. Email reputation asks whether the address or its infrastructure has been seen doing harm — a security question. A scam address often verifies perfectly; a safe address can bounce. Fraud screening needs the reputation answer, and ideally both.
Check the whole message, not just the sender
Scam emails carry more indicators than the from-address: payment links, lookalike domains, callback phone numbers, crypto wallets. Pasting the full message into the lookup extracts and checks every indicator at once, which catches campaigns where the sender address is fresh but the payment infrastructure is already known.
Automating email screening over the API
The same verdict is available over REST for signup flows, CRM hygiene, and SOC playbooks. Screen addresses in bulk, combine the email verdict with domain and URL checks, and keep the evidence trail attached to every decision your pipeline makes.
Frequently asked questions.
How do I check if an email address is a scam?
Does this reveal who owns an email address?
Can I detect disposable or temporary email addresses?
Can I check emails through the API?
Related articles. Learn more from our security research blog.
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