ASP.Net SMTP: System.ArgumentException: The parameter address cannot be an empty string

System.ArgumentException: The parameter 'address' cannot be an empty string. Parameter name: address at System.Net.Mail.MailAddress..ctor(String address, String displayName, Encoding displayNameEncoding) at System.Net.Mail.MailAddress..ctor(String address)

i checked verything the mail is sent  message.From = new MailAddress(frmemail);               message.To.Add(new MailAddress(toemail)); i get the address fo rthe same i get error after send i mean after this line  client.Send(message); and if the address was empty how is the mail recd