Email Abuse & Verification Glossary

Disposable email address

A temporary inbox that self-destructs after a short period — typically 10 minutes to 24 hours — created instantly and without registration on services like Mailinator, 10MinuteMail, or Guerrilla Mail. Also called temp mail, throwaway email, or burner email.

Disposable addresses can receive verification emails, which is why simple "send a confirmation link" flows don't stop them. Deep dive: What Are Disposable Emails?

Temp mail

Shorthand for temporary email. Usually refers both to the address itself and to the category of services that provide them (temp-mail.org being one of the most popular). Functionally identical to disposable email — the terms are interchangeable.

Burner email

An email address created for one-time or short-term use and then abandoned, named after "burner phones". Some burners are disposable-service addresses; others are real accounts (e.g. a spare Gmail) used once. Only the former can be caught by domain-based detection.

Catch-all address

A mail server configuration that accepts email sent to any address at a domain, even addresses that were never explicitly created. Disposable providers rely on catch-alls to offer unlimited instant inboxes; businesses sometimes use them to avoid missing mail. Catch-all temp servers can be detected by their MX record fingerprints.

Plus addressing (sub-addressing)

A feature of Gmail, Outlook, and other providers where user+anything@gmail.com delivers to user@gmail.com. It's often confused with disposable email but is fundamentally different: the underlying mailbox is real and permanent. TempMailChecker does not flag plus-addressed emails.

Email validation

Checking whether an address is usable and trustworthy without necessarily contacting the mailbox: syntax checks, domain existence, MX records, and disposability. Fast enough to run inline during signup. See email validation API best practices.

Email verification

A deeper (and slower) form of validation that connects to the recipient's mail server over SMTP to confirm the specific mailbox exists. Used for bulk list cleaning rather than real-time signup checks — SMTP probes can take seconds and are often blocked or inconclusive for large providers.

MX record

A DNS record specifying which mail servers accept email for a domain. A domain with no MX record (and no fallback A record) can't receive mail, so MX lookups are a basic validity check. But MX checks alone can't catch disposable domains — temp services have perfectly valid MX records.

SPF (Sender Policy Framework)

A DNS TXT record listing the servers authorized to send email on behalf of a domain. Receivers check the connecting IP against it to detect forged senders. Check any domain with our free SPF analyzer.

DKIM (DomainKeys Identified Mail)

Cryptographic signing of outgoing email. The sending server signs each message with a private key; receivers verify it against the public key published in DNS, proving the mail came from the domain and wasn't modified in transit. Test your setup with the DKIM analyzer.

DMARC

Domain-based Message Authentication, Reporting & Conformance. A DNS policy that tells receiving servers what to do with email failing SPF/DKIM (nothing, quarantine, or reject) and where to send reports. Required by Gmail and Yahoo for bulk senders since 2024. Inspect any domain's policy with the DMARC analyzer.

Free trial abuse

Repeatedly signing up for a product's free tier or trial using different email addresses — usually disposable ones — to keep consuming paid value for free. Especially costly for AI products and anything with per-account compute or credits. See how disposable emails enable free trial abuse.

Promo / coupon abuse

Creating multiple accounts with throwaway emails to redeem one-time discount codes, referral bonuses, or welcome credits again and again. A single abuser with a temp mail generator can drain a promotion budget in hours. See stopping promo code abuse.

Multi-accounting

One person operating many accounts on the same platform to evade rate limits, manipulate votes and reviews, or spread risk across identities. Disposable emails are the standard enabler. See preventing multi-account fraud.

Ban evasion

Returning to a platform after a ban by creating a fresh account, typically with a new disposable address. Communities and marketplaces block temp mail at registration precisely to make bans stick.

False positive (email detection)

Flagging a legitimate address as disposable. It's the most expensive detection error — a blocked real user rarely retries. This is why list quality beats list size, and why we manually verify domains before adding them (false-positive rate below 0.01%).

Blocklist / blacklist

A maintained list of domains known to belong to disposable email services, checked at signup. Can be a static file (goes stale fast) or a managed API querying a continuously updated database. Browse recently added domains in ours.

Wildcard subdomain

DNS configured so any subdomain resolves — anything.tempmail.net, xyz123.tempmail.net, and so on. Disposable services use wildcards to mint unlimited "new" domains. Detection requires extracting and matching the parent domain, which our API does automatically.

Sender reputation

The trust score mailbox providers assign to your sending domain and IPs, based on bounce rates, spam complaints, and engagement. Disposable signups poison it: their addresses expire, your newsletters bounce, and your reputation (and inbox placement) drops.

Email deliverability

Whether your email actually lands in inboxes instead of spam folders. Driven by sender reputation, authentication (SPF/DKIM/DMARC), and list hygiene — which is why blocking disposable addresses at signup protects your entire email program downstream.