This is my code..
var client = new SendGridClient(SendGridEmailEntity.Key);
var from = new EmailAddress(SendGridEmailEntity.Mail, SendGridEmailEntity.DisplayName);
var subject = templateRecord.EmailFrm.SubjectName;
var to = new EmailAddress(activeQueueEntities[i].EmailId, activeQueueEntities[i].Name);
var plainTextContent = "";
var htmlContent = templateRecord.TemplateContent;
var msg = MailHelper.CreateSingleEmail(from, to, subject, plainTextContent, htmlContent);