import type { DKIMConfig, Envelope, MailOptions } from "./types.js";
/** Result of building a complete MIME message. */
export interface MIMEBuildResult {
    /** Complete raw MIME message bytes ready to send. */
    raw: Uint8Array;
    /** SMTP envelope derived from From/To/Cc/Bcc. */
    envelope: Envelope;
    /** Message-ID assigned or supplied for the message. */
    messageId: string;
    /** Size of the raw MIME message in bytes. */
    size: number;
}
/**
 * Build a complete MIME message as a Uint8Array ready for SMTP DATA.
 * When `dkim` is provided, signs the message and prepends the DKIM-Signature header.
 */
export declare function buildMIME(options: MailOptions, dkim?: DKIMConfig): Promise<MIMEBuildResult>;