Email multiple receipients

Hi, I need to generate a report from my db and send it to multiple recipients. I have a challenge as described below:

I am using the following code:
private void lnkbEmailWeeklyReports_Click(object sender, System.EventArgs e)
{

MailMessage mail = new MailMessage();
mail.To = "abc@xyz.com;def@xyz.com;mno@xyz.com";

mail.From = "abc@xyz.com";

mail.Subject = "Area Weekly Reports.";

mail.Body = "this is my test email body for Weekly Reports";

SmtpMail.SmtpServer = "xxxxxxx"; //real s ...