Wingate proxy server

Dear Sir,
I have a problem that my network adinistrater watches me and he use to enter in my mails.
The matter is i uses the internet in a internet club, the owner have 5 PC’s as client and 1 PC as server. He uses the Wingate proxy server. With the Wingate he is able to to check and reach what we are doing, even sometimes he entered in our mails.
As u know that to enter in someones mails is absolutely disguisting and stupidity. he is just destroying our privacy, he hasnt any legal restriction for this.
So Sir, i humbly requests u that tell me how i can prevent in doing this, how i can secure my privacy???
I hopes a quick reply from ur side, please.
Thanking u in Advance
Regards.
Sincerely,
Mohammad Saqib Ali.