Cannot implicitly convert type 'string' to 'System.Net.Mail.MailAddress'

I got error "Cannot implicitly convert type 'string' to 'System.Net.Mail.MailAddress' "

MailMessage msg = new MailMessage();
msg.From = "info@xxx.com";
msg.To = "comments@xx.com";
msg.Bcc = "keith@xxx.com";
msg.Subject = "Comment";
msg.Body = "Comment: xxxxxxx xxxxxxx xxxxxxx ";
SmtpClient smtpClient = new SmtpClient();
smtpClient.Host = Global.smtp;

To solve the issue, i change to below code

MailMessage msg = new MailMessage();
msg.From = new System.Net.Mail.MailAddress("info@xxx.com");
msg.To.Add("comments@xx.com");
msg.Bcc.Add("keith@xxx.com");
msg.Subject = "Comment"; msg.Body = "Comment: xxxxxxx xxxxxxx xxxxxxx ";
SmtpClient smtpClient = new SmtpClient();
smtpClient.Host = Global.smtp;