/**
 * Post-hoc classifier for free-form SMTP error messages.
 *
 * The library's own probe (`smtp-verifier.ts`) classifies live SMTP replies at
 * the wire level — that flow does not use this function. `parseSmtpError` is
 * a public utility for callers who have a flattened error string in hand
 * (e.g. `result.smtp.error`, the `message` of a thrown exception, or a
 * provider-specific bounce message logged elsewhere) and want a structured
 * verdict.
 *
 * Returns four orthogonal signals:
 *   - `isDisabled`    — recipient does not exist / account locked / blocked
 *   - `hasFullInbox`  — quota / storage limit / 452 / 552
 *   - `isCatchAll`    — domain accepts every recipient
 *   - `isInvalid`     — caller-friendly default: nothing else matched and the
 *                       error isn't a known transient/rate-limit pattern
 *
 * The categories are independent — a single message can be both `isDisabled`
 * and `hasFullInbox` if its text matches both groups.
 */
export interface ParsedSmtpError {
    isDisabled: boolean;
    hasFullInbox: boolean;
    isCatchAll: boolean;
    isInvalid: boolean;
}
/**
 * Classify a free-form SMTP error message. Empty / null input returns the
 * "everything-false except isInvalid" shape since we have no signal.
 */
export declare function parseSmtpError(errorMessage: string): ParsedSmtpError;