Mail Notification on Server Up and Down

The Following Features has been added:-

1) Whenever a server goes down he will get notified i.e. the account creator with an email, that the server has gone down. 

2) Same thing will happen when a server will come back.

3) A new model "ServerHistory" has been created for this purpose which stores status history of all the servers. New code checks the server history and compare it with current status of each server. If the server status has been changed, than last status, he will get mail.