}
// Dial returns a new Client connected to an SMTP server at addr.
-// The addr must include a port number.
+// The addr must include a port, as in "mail.example.com:smtp".
func Dial(addr string) (*Client, error) {
conn, err := net.Dial("tcp", addr)
if err != nil {
// possible, authenticates with the optional mechanism a if possible,
// and then sends an email from address from, to addresses to, with
// message msg.
+// The addr must include a port, as in "mail.example.com:smtp".
//
// The addresses in the to parameter are the SMTP RCPT addresses.
//