internal Message(string from, string to) : this()
{
if (from == null)
throw new ArgumentNullException(nameof(from));
if (to == null)
throw new ArgumentNullException(nameof(to));
if (from == string.Empty)
throw new ArgumentException(SR.Format(SR.net_emptystringcall, nameof(from)), nameof(from));
if (to == string.Empty)
throw new ArgumentException(SR.Format(SR.net_emptystringcall, nameof(to)), nameof(to));
_from = new MailAddress(from);
MailAddressCollection collection = new MailAddressCollection();
collection.Add(to);
_to = collection;
}