type Options = {
    sender: string;
    validateRegex: boolean;
    validateMx: boolean;
    validateTypo: boolean;
    validateDisposable: boolean;
    validateSMTP: boolean;
};
type MailCheckOptions = {
    additionalTopLevelDomains?: string[];
};
type ValidatorOptions = Partial<Options> & {
    email: string;
} & MailCheckOptions;

declare global {
    interface ObjectConstructor {
        typedKeys<T>(o: T): Array<keyof T>;
    }
}
type ElementType<T extends ReadonlyArray<unknown>> = T extends ReadonlyArray<infer E> ? E : never;

declare const OrderedLevels: readonly ["regex", "typo", "disposable", "mx", "smtp"];
type SubOutputFormat = {
    valid: boolean;
    reason?: string | undefined;
};
type Level = ElementType<typeof OrderedLevels>;
interface GeneralOutputFormat extends SubOutputFormat {
    reason?: Level | undefined;
}
type OutputFormat = GeneralOutputFormat & {
    validators: {
        [K in Level]?: SubOutputFormat;
    };
};

declare function validate(emailOrOptions: string | ValidatorOptions): Promise<OutputFormat>;

export { validate as default, validate };