Can't login to Tuitalker

hello,

I have downloaded tuitalker free software.
and created an account on that.
my account is successfully activated.
but whenever i trying to login through tuitalker,it says "connection error
trying in 0:20 seconds"

I also checked that my internet connection is working properly by opening some websites
but i can't login.my email and password is also right.

please give me a solution to login and use tuitalker.
thanks.