import type SMTPTransport from 'nodemailer/lib/smtp-transport';
export type SmtpOptions = SMTPTransport.Options;
export interface Notifier {
    sendActivationCode(email: string, activationCode: string): Promise<unknown>;
}
export declare const logNotifier: Notifier;
export declare class SmtpNotifier implements Notifier {
    private readonly transporter;
    private readonly from;
    private readonly domain;
    /**
     * @param options SMTP options
     * @param name gateway domain, used as a default self hostname
     * @see https://community.nodebb.org/post/81300
     */
    constructor({ smtp: options, '@domain': name }: {
        smtp?: SmtpOptions;
        '@domain': string;
    });
    sendActivationCode(email: string, activationCode: string): Promise<SMTPTransport.SentMessageInfo>;
}