Arduino Ethernet Shield Webserver voltage sensore and send mail

Hello all

is my first time here so i dont now if im post that on the whrite topic i hope that this is sry for my english to
im not so good.
i have a andruino uno with arduino ethrnet shield 2 up on and a voltage sensore what i want to do is
to make a wedserver so i can check at any time the analog input if the voltage is up but also i want in a case that tha voltage go 0 to send me an e mail that power is down.
anyone now if ther is ready code for that or anyone can help me on that plz thank you.