Error sending mail C Sharp

For 16 RAM servers I have no problems, mail is sent normally, but with servers with less RAM, I can not send emails.

I have added the following as the waiting time but the problem persists.

            SmtpClient client = new SmtpClient();
            client.Host = ConfigurationManager.AppSettings["HostCorreo"];
            client.Port = int.Parse(ConfigurationManager.AppSettings["PuertoCorreo"]);
            client.EnableSsl = true;
            client.Timeout = 2147483647;
            client.DeliveryMethod = SmtpDeliveryMethod.Network;
            client.UseDefaultCredentials = false;
            client.Timeout = 214748

What should I do to solve this problem?

The error message is as follows, it finally appears as if it were being sent, but the emails are never sent.