php – 如何执行函数直到成功？

我想要做的是,如果发生错误,我想继续发送邮件,直到邮件发送.

function sendmail() {
        $name = mysql_escape_string($name);
        $email = mysql_escape_string($email);
        $phone = mysql_escape_string($phone);
        $content = nl2br(mysql_escape_string($content));
        $subject = "mail from ".$name." (".$email.",Ph: ".$phone.")";
        $mail = @mail($feedback,$subject,$content,$headers);
        if($mail) { echo "Your mailis send"; }
        else { echo "We are sorry for the inconvienience,but we could not send your mailnow."; }
}

上面的函数显示错误消息,但我想尝试发送邮件,直到最后发送邮件为止.