import type { Cache } from './cache-interface';
/**
 * Validates if email domain is valid TLD
 */
export declare function isValidEmailDomain(emailOrDomain: string, cache?: Cache | null): Promise<boolean>;
/**
 * Validates email-address format with a pragmatic (not strictly RFC-5322) regex.
 *
 * The local-part allow-list is `[a-zA-Z0-9._+'-]` — letters, digits, dot,
 * underscore, plus, apostrophe, hyphen. Characters that are technically valid
 * in RFC atext but virtually never appear in real mailboxes (`= ? ^ ~ { } | *
 * & % $ # ! / `` `) are rejected. Quoted local-parts (`"..."@example.com`) are
 * accepted as-is — they're rare but legal — but their interior is not parsed.
 */
export declare function isValidEmail(emailAddress: string): boolean;