发送邮件封装的方法

/// <summary>
        /// 发送邮件
        /// </summary>
        /// <param name="fromMail">发件人邮箱</param>
        /// <param name="toMail">收件人邮箱</param>
        /// <param name="subject">主题</param>
        /// <param name="body">内容</param>
        /// <param name="clientHost">设置用于 SMTP 事务的主机的名称或 IP 地址</param>
        /// <param name="roleCode">生成授权码</param>
        /// <returns></returns>
        public static bool SendMessage(string fromMail, string toMail, string subject, string body, string clientHost, string roleCode)
        {
            MailMessage mailMessage = new MailMessage();
            //发件人邮箱
            mailMessage.From = new MailAddress(fromMail);
            //收件人邮箱
            mailMessage.To.Add(new MailAddress(toMail));
            //主题
            mailMessage.Subject = subject;
            //内容
            mailMessage.Body = body;
            mailMessage.Sender = new MailAddress(fromMail);
            SmtpClient client = new SmtpClient();
            client.Host = clientHost;
            //使用安全加密连接。
            client.EnableSsl = true;
            //不和请求一块发送。
            client.UseDefaultCredentials = false;
            //验证发件人身份(发件人的邮箱，邮箱里的生成授权码);
            client.Credentials = new NetworkCredential(fromMail, roleCode);
            //发送
            try
            {
                client.Send(mailMessage);
            }
            catch (Exception ex)
            {
                return false;
            }
            return true;

        }