/**
 * Address parsing and grouping — aligned with the legacy `sendmail` npm package
 * (guileen/node-sendmail) behavior for recipient grouping and domain extraction.
 */
/** Extract bare email from `Name <email@domain>` or return trimmed input (linear time, no regex). */
export declare function extractEmail(address: string): string;
/** Split address lists (legacy package accepted both string and array). */
export declare function parseAddressList(addresses: string | string[] | undefined): string[];
/** Domain part of an email address (after the last `@`). */
export declare function getHostFromAddress(email: string): string | undefined;
/** Group recipient addresses by recipient domain (MX routing key). */
export declare function groupRecipientsByDomain(recipients: string[]): Record<string, string[]>;
/** Collect all recipients from to / cc / bcc (same sources as legacy sendmail). */
export declare function collectRecipients(mail: {
    to?: string | string[];
    cc?: string | string[];
    bcc?: string | string[];
}): string[];
//# sourceMappingURL=addressing.d.ts.map