import { Options } from 'nodemailer/lib/mailer';
interface MXRecord {
    exchange: string;
    priority: number;
}
interface tlsInterface {
    key: string;
    cert: string;
}
interface MailDoveOptions {
    smtpPort?: number;
    smtpHost?: string;
    dkimEnabled?: boolean;
    dkimPrivateKey?: string;
    dkimKeySelector?: string;
    startTLS?: boolean;
    rejectUnauthorized?: boolean;
    tls?: tlsInterface;
}
declare class MailDove {
    smtpPort: number;
    smtpHost?: string;
    dkimEnabled: boolean;
    dkimPrivateKey: string;
    dkimKeySelector: string;
    startTLS: boolean;
    rejectUnauthorized: boolean;
    tls: tlsInterface;
    private step;
    private queue;
    private upgraded;
    private isUpgradeInProgress;
    private sock;
    constructor(options: MailDoveOptions);
    /**
     * Resolve MX records by domain.
     * @param {string} domain
     * @returns {Promise<MXRecord[]>}
     */
    resolveMX(domain: string): Promise<MXRecord[]>;
    sendToSMTP(domain: string, srcHost: string, from: string, recipients: string[], body: string): Promise<string>;
    writeToSocket: (s: string, domain: string) => void;
    parseInputAndRespond(line: string, domain: string, srcHost: string, body: string, connectedExchange: string, resolve: any): void;
    handleResponse(code: number, msg: string, domain: string, srcHost: string, body: string, connectedExchange: string, resolve: any): void;
    /**
     *  Send Mail directly
     * @param mail Mail object containing message, to/from etc.
     * Complete attributes reference: https://nodemailer.com/extras/mailcomposer/#e-mail-message-fields
     * @returns {Promise<string[]>}
     */
    sendmail(mail: Options): Promise<string[]>;
}
export { MailDove };