public class EmailService : IIdentityMessageService
{
    public Task SendAsync(IdentityMessage message)
    {
        // Credentials:
        var sendGridUserName = "myusername";
        var sentFrom = "test@email.com";
        var sendGridPassword = "mypassword";

        // Configure the client:
        var client =
            new System.Net.Mail.SmtpClient("smtp.sendgrid.net", Convert.ToInt32(587));

        client.Port = 587;
        client.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;
        client.UseDefaultCredentials = false;

        // Creatte the credentials:
        System.Net.NetworkCredential credentials =
            new System.Net.NetworkCredential(sendGridUserName, sendGridPassword);

        client.EnableSsl = true;
        client.Credentials = credentials;

        // Create the message:
        var mail =
            new System.Net.Mail.MailMessage(sentFrom, message.Destination);

        mail.Subject = message.Subject;
        mail.Body = message.Body;

        // Send:
        return client.SendMailAsync(mail);
    }
}