You can check out Azure's SendGrid Email Service for it over here: https://docs.microsoft.com/en-us/azure/sendgrid-dotnet-how-to-send-email
You can also configure your SMTP client, create a message and send the email.
Follow the given steps to do so :
// create the message
var msg = new MailMessage();
msg.From = new MailAddress("[email protected]");
msg.To.Add(strTo);
msg.Subject = strSubject;
msg.IsBodyHtml = true;
msg.Body = strMessage;
// configure the smtp server
var smtp = new SmtpClient("YourSMTPServer");
var = new System.Net.NetworkCredential("YourSMTPServerUserName", "YourSMTPServerPassword");
// send the message
smtp.Send(msg);