/// <reference types="node" />
import { SendMailOptions } from 'nodemailer';
import { SmtpOptions } from 'nodemailer-smtp-transport';
import { Readable } from "stream";
export declare const MailerConfig: unique symbol;
export declare class MailerService {
    private config;
    private transport;
    constructor(config: IMailerConfig);
    private createTransport;
    sendMail(data: SendMailOptions): Promise<any>;
    sendMailWithConfig(config: IMailerConfig, data: SendMailOptions): Promise<any>;
    verifyConfig(config: IMailerConfig): Promise<void>;
    static addInlineImageAttachment(data: SendMailOptions, filename: string, content: string | Buffer | Readable): string;
}
export interface IMailerConfig {
    type: MailerType;
    options: SmtpOptions;
}
export declare enum MailerType {
    SMTP = "smtp",
    STUB = "stub"
}