Signup email risk checker: find fake signups in bulk
A signup email risk checker reviews a list of signup emails for the signals behind fake or low-quality accounts. This one flags disposable domains and disposable mail servers, domains that can't receive mail, parked domains, domains registered in the last 30 days, likely typos and role addresses, and gives a reason for each flag, so you decide what to block.
Sample result
2 of 5 signups look high risk: a disposable domain and a domain registered 6 days ago.
- Signups
- 5 addresses
- Disposable domain
- 1
- Brand-new domain
- 1
What this means for you
Block or review those rows, then verify the mailboxes on the signups you keep.
- Disposable, parked and dead domains
- Domain age from the registry (RDAP)
- Typos and role addresses, in your browser
- 100 domains a run, 500 signed in; CSV
- Signups
- Fraud
- Bulk
By SimpleVerifier Team · Last updated
How do I check a list of signups for fake emails?
- Paste signup emails, one per line, or upload your signup export as a CSV; the email column is found for you.
- Press Check signup risk. Syntax, typos and role prefixes are checked in your browser, and the unique domains are looked up on our server, ten at a time.
- Read each row: High risk, Review, Low risk or No flags, with every flag and its reason.
- Filter by risk and download the CSV to block, review or verify the rows.
Example
- You enter
- A signup export with
jane@acme.example,sam@mailinator.com,lee@gmial.comandinfo@acme.example. - You get
sam@mailinator.comis High risk (disposable domain).lee@gmial.comis Review (likely typo of gmail.com).info@acme.exampleis Low risk (role address).jane@acme.examplehas no flags. If acme.example had been registered in the last 30 days, both acme rows would also show Brand-new domain. Download the CSV with every flag and reason.- Limits
- Up to 100 unique domains a run without an account and 500 when signed in with Google. Only domains are sent; no mail server is contacted.
What makes a signup email risky?
Signals that the address was made to get past a form rather than to receive mail. High risk: a disposable domain, a domain whose MX points at a disposable service, a domain that can't receive mail at all, a domain on a parking service's nameservers, a domain registered in the last 30 days, or an address that breaks the syntax rules. Review: a likely typo of a big mail domain (gmial.com), a domain registered in the last 180 days, or one the registry has no record of. Low risk: a role address such as info@ or sales@.
Personal webmail such as Gmail or Outlook isn't a risk on its own and isn't flagged; it's shown as a label so you can tell consumers from companies.
Where does the domain age come from?
From the registry's RDAP record, the same source as our domain age checker. It's looked up only for company domains: the age of gmail.com says nothing about the person signing up. Some country-code registries (.io, .co, .de and others) publish no RDAP, so those domains get no age flag. Answers are cached for six hours, and five registry lookups run at a time to stay polite to the registries.
Should I block every flagged signup?
No. Block the high-risk rows that matter for your product (disposable and dead domains are rarely real customers), review the rest, and remember that a brand-new company domain can belong to a real startup. Every flag says which check raised it, so you can choose your own rules. To stop them at the form, see how to stop fake signups.
What doesn't it check?
Whether the mailbox exists. That needs a conversation with the mail server, which is what email verification does. It also doesn't look at IP addresses, devices or behaviour, which fraud tools combine with email signals; this checker only uses what the address and its domain show.
How is this different from a fraud scoring API?
| This checker | Fraud scoring APIs | |
|---|---|---|
| Signals | Email and domain only | Email, IP, device and behaviour |
| Output | Flags with the reason for each | Usually a single score |
| Setup | Paste or upload a list | API integration |
| Best for | Reviewing an export | Blocking at signup in real time |
Who uses this tool, and for what?
- SaaS teams
- Review last week's trial signups and find the throwaway and dead-domain accounts before they skew activation numbers.
- Growth and fraud teams
- Spot bursts of signups on brand-new or parked domains, a common pattern in trial and referral abuse.
- Ecommerce
- Check customer exports for fake accounts behind coupon and first-order discount abuse.
- Community and event managers
- Clean a registration list before sending joining details.
What can’t this tool tell you?
- Flags are signals, not proof; a new company domain can belong to a real business.
- Domain age needs RDAP, which some country-code registries don't publish.
- It doesn't check whether the mailbox exists, or look at IPs and devices.
- Up to 100 unique domains a run without an account, 500 signed in.
Common questions
- How do I check if signups are fake?
- Export the signup emails and paste them here. Each is checked for disposable, parked, brand-new or dead domains, typos and role addresses, and every flag comes with its reason.
- What counts as a new domain?
- One the registry says was registered in the last 30 days is flagged high risk, and one under 180 days is flagged for review. The date comes from the registry's RDAP record.
- Is this signup email risk checker free?
- Yes. It's a free tool with no card: 100 unique domains a run without an account and 500 when signed in with Google.
- Does it send my users' email addresses anywhere?
- No. Syntax, typo and role checks run in your browser. Only the domains are sent to our server for the disposable, MX, registry and nameserver lookups, and nothing is stored.
- Is a Gmail signup risky?
- Not by itself. Personal webmail is labelled so you can separate consumers from companies, but it's only flagged when something else is wrong, such as a typo or broken syntax.
- Can I use it on a whole signup export?
- Yes. Upload the CSV and the email column is found automatically. The limit counts unique domains, so an export with thousands of Gmail addresses still fits.
Sources
Every address left in your cleaned list still need a mailbox check.
This tool removed what can be found without contacting a mail server. Whether each remaining mailbox actually exists can only be answered by asking the server that hosts it — an SMTP check — and that is what the paid plan does.
- Upload the cleaned file as it is — CSVs up to 100,000 rows
- A real SMTP mailbox check on every row, with catch-all detection
- Valid, risky and invalid exported as separate files
One plan, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.