c# - Angular 项目中的 SMTP 电子邮件和 ERR_CONNECTION_RESET 错误

Question

嗨，当我在 angular api 项目中使用下面的代码时，我的请求没有得到保存，我得到了以下错误。当我评论发送邮件的代码时，一切正常

控制台中的错误

 polyfills POST net::ERR_CONNECTION_RESET

和发送邮件的代码

 public async Task SendEmail(string email, string subject, string firstName, string contact)
    {
        try
        {
            string message = BuildMessageBody(firstName, email, contact);

            using (var client = new SmtpClient())
            {
                var networkCredential = new NetworkCredential
                {
                    UserName = _configuration["Email:Email"],
                    Password = _configuration["Email:Password"]
                };

                client.UseDefaultCredentials = false;
                client.Credentials = networkCredential;
                client.Host = _configuration["Email:Host"];
                client.Port = int.Parse(_configuration["Email:Port"]);
                client.EnableSsl = true;

                using (var emailMessage = new MailMessage())
                {
                    emailMessage.To.Add(new MailAddress(email));
                    emailMessage.CC.Add(new MailAddress("my cc adddress"));
                    emailMessage.From = new MailAddress(_configuration["Email:Email"]);
                    emailMessage.Subject = subject;
                    emailMessage.Body = message;
                    emailMessage.IsBodyHtml = true;
                    emailMessage.BodyEncoding = System.Text.Encoding.UTF8;
                    emailMessage.SubjectEncoding = System.Text.Encoding.Default;
                    emailMessage.ReplyToList.Add(new MailAddress(_configuration["Email:Email"]));

                    client.SendCompleted += (s, e) => {
                        client.Dispose();
                        emailMessage.Dispose();
                    };
                    await client.SendMailAsync(emailMessage);
                }
            }
            await Task.CompletedTask;
        }
        catch (Exception ex)
        {
            _appLogger.CreateLog("SendEmail - " + ex.Message);
        }
    }

知道为什么会有这种行为吗？？？