Email Provider for sending email

EmailProvider.cs

public class EmailProvider : IEmailProvider
    {
        private readonly SmtpClient smtpClient = null;
        private readonly IEmailTemplateRepository _emailRepository;
        private bool disposed = false;

        private EmailProvider()
        {
            smtpClient = new SmtpClient();
        }

        public EmailProvider(IEmailTemplateRepository emailRepository) : this()
        {
            _emailRepository = emailRepository;
        }

        public EmailProvider(string smtpAddress, int portNumber, string userName, string password) 
        {
            smtpClient = new SmtpClient(smtpAddress, portNumber);
            smtpClient.Credentials = new NetworkCredential(userName, password);
        }

        public void Send(MailMessage message)
        {
            if (disposed) throw new ObjectDisposedException("Email Provider not able to send email after dispose");

            if (message == null) throw new ArgumentNullException("Email message argument can't be null");

            if (message.To == null || !message.To.Any()) throw new Exception("Recipients are not specified");

            var recipientList = string.Join(",", message.To.Select(x => x.Address).ToArray());
            try
            {
               smtpClient.Send(message);
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

        public void Send(string to, string subject, string body = "", bool isHtml = true, string from = "")
        {
            if (String.IsNullOrEmpty(to) && String.IsNullOrEmpty(subject))
                throw new Exception("Recipient or subject can't be null or empty");
            var mailMessage = new MailMessage();
            var toEmail = new MailAddress(to);
            mailMessage.To.Add(toEmail);
            mailMessage.Subject = subject;
            mailMessage.Body = body;
            mailMessage.IsBodyHtml = isHtml;
            this.Send(mailMessage);
        }

        public void Send(string to, TemplateTypes type, object bindableContext, string from = "")
        {
            if (type == 0)
                throw new ArgumentNullException("Specify the valid template type");
            var content = _emailRepository.GetTemplateByType(type);
            if (content == null)
                throw new BusinessException(String.Format("No {0} Template exist in system", type.ToString()));
            var subjectBindableFunc = Handlebars.Compile(content.EmailSubject);
            var bodyBindableFunc = Handlebars.Compile(content.TemplateContent);
            Send(to: to, subject:subjectBindableFunc(bindableContext), body:bodyBindableFunc(bindableContext), from: from);
        }

        private void Dispose(bool disposing)
        {
            if(disposing)
            {
                if (!disposed)
                {
                    if (smtpClient != null)
                        smtpClient.Dispose();
                    disposed = true;
                }
            }
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        ~EmailProvider()
        {
            Dispose(false);
        }


     
    }

IEmailProvider.cs

public interface IEmailProvider : IDisposable
{
    void Send(MailMessage message);
    void Send(string to, string subject, string body = "", bool isHtml = true, string from = "");
    void Send(string to, string subject, string templateName, object bindableContext, string from = "");
}