使用 SMTP 客户端发送电子邮件

Question

I am trying to send an email using SMTP client using my gmail credential. This is the code am using

        using (var mail = GetMailInfo())
        {
            using (SmtpClient client = new SmtpClient("smtp.gmail.com", 465))
            {
                    client.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;
                    client.Credentials = new NetworkCredential("**@gmail.com", "Password");
                    client.UseDefaultCredentials = false;
                    client.EnableSsl = true;
                    client.Send(mail);
            }
        }

I receive a time out error

The operation has timed out

If I try again I get another error saying

Service not available, closing transmission channel. The server response was: Too many concurrent SMTP connections; please try again later.

What am I doing wrong?

Answer 1

At last I figure it out what was wrong with my code Updated code is below

using (var mail = GetMailInfo())
    {
        using (SmtpClient client = new SmtpClient("smtp.gmail.com", 587)) // port is 587 instead of 465 as mentioned by @jdweng in the comment
        {
                client.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;
                client.UseDefaultCredentials = false; // this must be before the **Credentials** else this will reset the given credential                   
                client.Credentials = new NetworkCredential("**@gmail.com", "Password");
                
                client.EnableSsl = true;
                client.Send(mail);
        }
    }

On the top if you are using gmail go to settings and deactivate 2 way authentification and Access for less secure apps should be Activated

All these can be found Here