invalid_syntax

The input does not parse as an email address

Even after Spaw strips display names, mailto: links, quotes and invisible characters, what is left is not a syntactically valid address, so nothing else was checked.

appears in
reason
verdict
undeliverable
credits
Free. Invalid input never costs a credit.

What it means

Spaw first pulls the address out of whatever was pasted: a display name such as Mia K <[email protected]>, a mailto: link, spreadsheet quotes, trailing punctuation, zero-width and non-breaking characters are all removed. What remains is parsed against RFC 5322. invalid_syntax means that even after that cleanup there is no address to check: a missing @, a domain without a top-level label, spaces inside the username, or a bare word.

Because no domain could be extracted, every other field in the response is null, syntax_valid is false, and the risk score is fixed at 100.

What to do

Fix the input before retrying. When the value comes from a form, show the user the exact value that was checked (it is echoed in the email field) so a paste error is easy to spot.

Example response

{
    "email": "mia@acme",
    "deliverable": "undeliverable",
    "reason": "invalid_syntax",
    "syntax_valid": false,
    "risk_score": 100
}

Abbreviated: a real answer carries all 27 fields, listed in the verify-email reference.

Related

markdown version: /docs/reasons/invalid_syntax.md