Add a byte[] as attachment in a mail

In the game I capture a screenshot and I'd like to send it via mail.

Is it possible to send it wihtout saving the file to the hard drive?

I tried mail.Attachments.Add(screenshotFile);

But I need to change the byte[] to attachment. Is it possible to do that? (I'm using gmail as smtp).

My code is the following:

 static public void GmailSend (string mail, string subject, string body)
     {
         MailMessage mail = new MailMessage();
         
         mail.From = new MailAddress("email@email.here");
         mail.To.Add(mail);
         mail.Subject = subject;
         mail.Body = body;
 
 
         **//add a byte[] attachment to the Mail here**

 
         SmtpClient smtpServer = new SmtpClient(senderSmtp);
         smtpServer.Port = senderPort;
         smtpServer.Credentials = new System.Net.NetworkCredential(senderEmail, senderPassword) as ICredentialsByHost;
         if (sslEnabled){
             smtpServer.EnableSsl = true;
             ServicePointManager.ServerCertificateValidationCallback = 
                 delegate(object s, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors) 
             { return true; };
         }
         smtpServer.Send(mail);
         Debug.Log("success");
         
     }