MailMessage mail = new MailMessage();
mail.From = new MailAddress("login@yandex.ru", "Name");
mail.To.Add(account.Email);
mail.Subject = "Hello";
mail.Body = "Hello from Asp.net mvc";
mail.IsBodyHtml = true;
SmtpClient client = new SmtpClient();
client.Host = "smtp.yandex.ru";
client.Port = 587;
client.Credentials = new NetworkCredential("login@yandex.ru","password");

client.Send(mail);

db.Registration.Add(account);
db.SaveChanges();

public static void SendEmail(string email, string text, string subject)
    {
        MailAddress from = new MailAddress("aspnet.confirmation@yandex.ru", "ASP.NET Blog");
        MailAddress to = new MailAddress(email);
        MailMessage message = new MailMessage(from, to);
        message.Subject = subject;
        message.Body = text;
        message.IsBodyHtml = true;
        SmtpClient smtp = new SmtpClient("smtp.yandex.ru", 25);
        smtp.Credentials = new System.Net.NetworkCredential("aspnet.confirmation@yandex.ru", "yourpassword");
        smtp.EnableSsl = true;
        smtp.Send(message);
    }

public static void SendEmail(string title, string text, string emailTo, bool isBodyHtml = false)
{
    try
    {
        MailMessage mail = new MailMessage();
        mail.IsBodyHtml = isBodyHtml;
        mail.From = new MailAddress(ConstantsWeb.Email.Address.RobotEmail, ConstantsWeb.Global.CompanyName);
        mail.To.Add(emailTo);
        mail.Subject = title;
        mail.Body = text;
        mail.SubjectEncoding = Encoding.GetEncoding("utf-8");
        mail.Priority = MailPriority.Normal;
        SmtpClient SmtpServer = new SmtpClient(ConstantsWeb.Email.Server.Name)
        {
            Credentials = new NetworkCredential(ConstantsWeb.Email.Address.RobotEmail, ConstantsWeb.Email.Address.RobotEmailPassword),
            Port = ConstantsWeb.Email.Server.Port,
            EnableSsl = ConstantsWeb.Email.Server.UseSsl
        };

        SmtpServer.Send(mail);
    }
    catch(Exception e)
    {
        //do whatever...
    }
}