LicenseExpirationChecker.cs

using EPiServer.PlugIn;
using EPiServer.Scheduler;
using System;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Net.Mail;
using System.Reflection;
using System.Xml.Linq;

namespace Episerver_Playground.Business.Episerver_Jobs
{
    [ScheduledPlugIn(
        DisplayName = "License Expiration Checker", 
        Description = "Sends an email when your License.config is about to expire." +
        "The \"Scheduled job interval\" will set the frequency of sending the emails in combination with days of interval.",
        GUID = "{90B9C2F5-E1B1-4A34-B9FC-37AA4EC8C16F}",
        SortIndex = 1000)]
    public class LicenseSchedulerChecker : ScheduledJobBase
    {
        #region Properties

        private readonly int _daysOfInterval; 
        private readonly string _domainUrl; 

        #endregion

        public LicenseSchedulerChecker()
        {
            _daysOfInterval = 14; // recommended to set in configuration file
            _domainUrl = "http://consid.se"; // recommended to set in configuration file
        }

        public override string Execute()
        {
            OnStatusChanged(String.Format("Looking for your License..."));

            // Get the license file
            var directory = AppDomain.CurrentDomain.BaseDirectory;
            var licenseFile = Directory.GetFiles(directory, "License.config", SearchOption.AllDirectories).First();

            if (licenseFile == null)
            {
                return "License file couldn't be found!";
            }

            // Read the file
            XDocument file = XDocument.Load(licenseFile);
            var validationDateFromFile = file.Descendants("ValidToRestriction").First();

            // Get and convert date
            var dateValue = validationDateFromFile.FirstAttribute.Value;
            var validDate = DateTime.ParseExact(dateValue, "MM/dd/yyyy HH:mm:ss", CultureInfo.InvariantCulture);
            var validForDays = (validDate - DateTime.Now).TotalDays;

            // Check the date
            if (validForDays < _daysOfInterval)
            {
                return SendMail(validForDays, _domainUrl, dateValue);
            }

            return "License file is not in range of expiring.";
        }

        private static string SendMail(double validForDays, string domainUrl, string dateValue)
        {
            var result = string.Format("Mail was sent to {0}", "info@consid.se"); // recommended to set in configuration file

            // SMTP client
            using (var client = new SmtpClient
            {
                UseDefaultCredentials = true
            })
            {
                #region Mail setup
                MailMessage mail = new MailMessage();

                mail.From = new MailAddress("info@consid.se"); // recommended to set in configuration file
                mail.To.Add(new MailAddress("receiveraddress@hotmail.com")); // recommended to set in configuration file

                mail.Subject = string.Format("Warning! {0}'s license is about to expire!", domainUrl);
                mail.Body = "You're receiving this email because the Episerver license for <b>" + domainUrl + "</b> is about to expire!" +
                            "<br />" +
                            "Here is the due date and other information:" +
                            "<br />" +
                            "<br />" +
                            "<b>Domain:</b>" + domainUrl + "<br />" +
                            "<b>Project name:</b>" + Assembly.GetCallingAssembly().GetName().Name + "<br />" +
                            "<b>Valid to:</b> " + dateValue + "<br />" +
                            "<br />" +
                            "Not sure if you should receive these emails? Contact your administrator.";
                mail.IsBodyHtml = true;
                #endregion

                try
                {
                    client.Send(mail);
                }
                catch (Exception ex)
                {
                    result = "Email could not be sent. Check credentials and network settings for your SMTP.";
                }
            }

            return result;
        }
    }
}