Do not get in mail page

Do not get in mail page

Hi, 
I do not get to mail page
I log in, insert login, password, then go to  
https://home.zoho.com/home  
and hang in this, do not load page, do not get mail. Nothing.

I tried different brousers and different computers in office, but all the same, I do not get my mail. Problem only from office, I have no problem to get my mail from my home computers.
Our mail domain ovtr.net
Our IP 81.17.147.142