import nodemailer from 'nodemailer';
export declare class EmailProvider {
    private static _instance;
    private _smtpTransporter;
    /**
     * Return the instance of the EmailProvider.
     */
    static getInstance(): Promise<EmailProvider>;
    /**
     * Connect to the SMTP server and return the transporter instance.
     */
    connect(): Promise<nodemailer.Transporter>;
    /**
     * Send an email.
     * @param emailOptions - The email options.
     * @returns A promise that resolves when the email is sent.
     */
    send(sendMailOptions: nodemailer.SendMailOptions): Promise<void>;
}
export declare const emailProvider: EmailProvider;