/**
 * Secure SMTP Server Utility Functions
 * Provides helper functions for creating and managing secure TLS server
 */
import * as plugins from '../../../plugins.js';
/**
 * Create a secure TLS server for direct TLS connections
 * @param options - TLS certificate options
 * @returns A configured TLS server or undefined if TLS is not available
 */
export declare function createSecureTlsServer(options: {
    key: string;
    cert: string;
    ca?: string;
}): plugins.tls.Server | undefined;