var account = SendGridAccount.Create("API_USER", "API_KEY");

var account = SendGridAccount.Parse("ApiUser=API_USER;ApiKey=API_KEY");

// Get Blocklist
var blockList = await account.Blocks.GetAsync(new GetBlocksParameter { Limit = 10 });

// Delete all from Bounces
await account.Bounces.DeleteAsync(new DeleteBouncesParameter { DeleteAll = true });

// Send Mail
var sendMail = new SendMailParameter
{
    From = "from@example.com",
    Text = "text content",
    Html = "<p>html content</p>"
};

sendMail.To.Add("to@example.com");

await account.Mail.SendAsync(sendMail);