Fake signup protection is a real-time check on the email field of your signup form that rejects invalid, disposable and obviously fake addresses before the account is created. It runs in the fraction of a second between the user clicking submit and the record being saved. Catching bad addresses at entry is cheaper than cleaning them later and keeps your transactional and onboarding mail out of spam, because a database full of dead addresses pushes your bounce rate over the 2% line where providers start filtering you.
Three kinds of bad address reach a signup form. A mistyped real address ("gmail.con") that will bounce. A disposable address on a throwaway domain, used to grab a free trial or a lead magnet and abandoned minutes later. And an outright fake, invented to get past the form. All three inflate your user count, poison your onboarding emails, and drag down the sender reputation of the domain you rely on for password resets and receipts.
Cleaning them later is possible but expensive: you have already sent welcome mail that bounced, already counted them in your metrics, already let a trial abuser in. Blocking them at the form is a single check that costs a fraction of a cent and happens before any of that.
Mistyped and non-existent addresses, caught by syntax, MX and mailbox checks before the account is made.
Throwaway domains from a list updated daily, so trial abusers cannot sign up with a ten-minute mailbox.
Genuine addresses pass in under a second, so you add friction for abusers, not for customers.
Catch-all and role addresses are returned flagged, so you decide whether to allow, challenge or review them rather than hard-blocking a possible customer.
Your form sends the address to the validation API and gets back valid, invalid, disposable, catch-all or role in milliseconds. Reject or flag based on the verdict.
If the check ever times out, let the signup through rather than block a real customer. Verification is protection, not a gate that can take your form down.
Block invalid and disposable outright; decide per product whether to allow catch-all and role. A B2B tool may want to review role addresses; a consumer app may allow them.
Entry protection stops the worst, but addresses still decay. Re-verify the active base periodically; in our study only 19.2% of addresses were still valid 90 days after a check.
Add a real-time verification check to your signup form through an API. It checks the address the moment the user submits and rejects invalid and disposable addresses before the account is created, while letting real mailboxes through in under a second. Block the definite bad ones and flag the uncertain ones for review.
Yes. The verification check compares the domain against a disposable-domain list updated daily and returns a disposable flag, so your form can reject throwaway addresses used for trial abuse. Because new throwaway domains appear constantly, the list has to be current, which a maintained API handles for you.
Not if it is configured to fail open and to flag rather than hard-block the uncertain cases. Invalid and disposable addresses are safe to reject outright. Catch-all and role addresses are returned flagged so you can allow, challenge or review them, which avoids turning away a genuine customer on a cautious domain.
No meaningfully. The check returns in milliseconds and runs in the moment between submit and save. If it ever times out you let the signup through, so there is no case where the check itself stops someone from registering.
Usually yes, because the cost is tiny and the damage is not. A handful of disposable trial abusers or dead addresses can be absorbed, but they still skew your metrics and send bounced onboarding mail from the same domain you use for password resets. One API call at the form prevents all of it.
Add a real-time check to your form and reject invalid and disposable addresses at entry. Free tier covers 100 checks a month, with a real-time API.
Ayoub built BounceZero's 5-stage validation pipeline, its dedicated sending infrastructure, and the high-availability database behind every verification. Previously built high-volume email delivery systems. Trained at 1337 Benguerir (École 42 network, 2019). Open-source: bgp_analyzer.
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