How to turn on a proxy?

Есть такой код, хочу прикрутить ******, чтобы не кидало в спам и все сообщения доходили, помогите

MailMessage mail = new MailMessage();
SmtpClient cs = new SmtpClient("smtp.rambler.ru");
string nik = guna2TextBox7.Text;
mail.From = new MailAddress(MyEmails[schetchik], nik);
mail.To.Add(emails[i]);
mail.Subject = Subject;
mail.Attachments.Add(new Attachment(Pathis));
mail.Body = message;

cs.Port = 587;
cs.EnableSsl = true;
string log = MyEmails[schetchik];
string pass = MyEmails[schetchik + 1];
cs.Credentials = new NetworkCredential(MyEmails[schetchik], MyEmails[schetchik + 1]);
cs.Send(mail);

C#

 MailMessage mail = new MailMessage();

SmtpClient cs = new SmtpClient("smtp.rambler.ru");

string nik = guna2TextBox7.Text;

mail.From = new MailAddress(MyEmails[schetchik], nik);

mail.To.Add(emails[i]);

mail.Subject = Subject;

mail.Attachments.Add(new Attachment(Pathis));

mail.Body = message;



cs.Port = 587;

cs.EnableSsl = true;

string log = MyEmails[schetchik];

string pass = MyEmails[schetchik + 1];

cs.Credentials = new NetworkCredential(MyEmails[schetchik], MyEmails[schetchik + 1]);

cs.Send(mail);