# Email syntax validator Validate email address syntax offline, flag disposable domains and role-based mailboxes, and get a pass/fail verdict with a low/medium/high risk grade. ## Run it - **CLI:** `gizza tool email-syntax-validator "Ada Lovelace "` - **Web:** https://gizza.ai/tools/email-syntax-validator/ - **Agents:** machine-readable descriptor (parameters JSON Schema) at https://gizza.ai/tools/email-syntax-validator/tool.json ## Inputs - `email` — Email address _(field)_ - `check_disposable` — Flag disposable domains _(field)_ - `check_role` — Flag role-based addresses _(field)_ - `format` — Output format _(field)_ ## Output - Validation report (text) ## Query parameters Open the tool pre-filled and auto-run via URL: - `email` — Email address - `check_disposable` — Flag disposable domains - `check_role` — Flag role-based addresses - `format` — Output format Example: `https://gizza.ai/tools/email-syntax-validator/?email=Ada%20Lovelace%20%3Cada%40example.com%3E&check_disposable=true&check_role=true&format=report` --- ## About this tool Validate one email address before it enters a signup form, CSV import or allowlist. The tool combines practical RFC 5321/5322 syntax checking (including likely-typo suggestions) with a bundled disposable-domain list, then adds a role-address check for shared local parts such as `admin`, `info`, `sales`, `support`, `postmaster` and `abuse`. Every run returns a `pass`/`fail` verdict plus a `low`/`medium`/`high` risk grade. Bad syntax or a disposable domain is a `fail` at high risk; a deliverable address that is still worth a human look — a role alias, or a likely domain typo like `ada@gmial.com` — passes at medium risk. Worked example: `admin@mailinator.com` with both checks enabled returns `fail: admin@mailinator.com (syntax: valid, disposable: yes, role_based: yes, risk: high)` in summary format — the syntax is fine, but the domain is a known throwaway inbox and the local part is a role alias. Pick `report` for a labelled multiline breakdown, `summary` for a single line, or `json` for machine-readable fields (`valid`, `disposable`, `role_based`, `risk`, `verdict`, `errors`, `warnings`, `suggestion`). Turning a check off reports that category as `not checked` rather than as a clean result. This is an offline syntax and risk check. It does not perform DNS, MX, SMTP or mailbox-existence probes, so a `pass` verdict means the address is well-formed and not on the bundled risk lists, not that the mailbox can receive mail. It validates one address at a time; use a list cleaner for bulk workflows. ## FAQ
Does this contact the domain's mail server? No. The tool is intentionally offline and deterministic — the same address always produces the same result. It checks practical syntax rules, a bundled disposable-domain list and optional role-address patterns without any DNS, MX or SMTP network call, so nothing you paste leaves the page.
Why are role-based addresses flagged? Addresses like `info@`, `support@`, `admin@` and `postmaster@` usually reach a team or an automated queue rather than one person. They are perfectly deliverable, so they still get a `pass` verdict — but they are graded medium risk because many marketing, onboarding and abuse-prevention workflows want to review or block them. `no_reply@` is matched too: underscores are folded to hyphens before the lookup.
Is the disposable-domain list exhaustive? No. Disposable mail providers add domains constantly. The bundled list covers the common throwaway services and their alias domains and subdomains, plus a conservative throwaway-keyword heuristic — it is a fast, high-precision signal, not a registry. A `Disposable: no` result means "not on the known list", so pair it with your own policy for high-risk signups.
What is the difference between the verdict and the risk grade? The verdict answers "should this be accepted at all": it is `fail` only when the syntax is invalid or the domain is disposable. The risk grade adds nuance for everything that still passes — `medium` for a role alias or a likely domain typo, `low` for an ordinary personal address. Cosmetic notes, such as the address having had surrounding whitespace that was trimmed, appear under warnings but do not raise the risk grade.
## Related tools - [Email List Cleaner](https://gizza.ai/tools/email-list-cleaner/): Clean pasted email lists: validate syntax, trim and lowercase, remove duplicates, flag malformed rows, and export a copy-ready list. - [Email Validator](https://gizza.ai/tools/email-validator/): Validate an email address against RFC 5321/5322 syntax in your browser — flags bad domains, illegal characters and typos like gmial.com. Free, no DNS lookup. - [Form Field Validator](https://gizza.ai/tools/form-field-validator/): Validate a whole form locally: email, phone, URL, postal code, and credit card fields with required checks, locale hints, normalization, and JSON. - [Format Validator](https://gizza.ai/tools/format-validator/): Validate a value as an email address, URL, IPv4/IPv6 address, phone number, or credit card with Luhn check. Auto-detect formats locally in your browser. - [Absolute value, sign, or negation for a whole column](https://gizza.ai/tools/absolute-value-transformer/): Paste a column of numbers and apply absolute value, sign extraction (-1/0/1), sign flipping, or force-negative to every value at once, with rounding and an audit table.