If you are having broadband connection provided by BSNL , you can verify the usage up-to-date by logging in to any one of two below urls.
If you are using it first time you should get portal id from BSNL. For getting portal id we can call the BSNL customer care number 1500.
For any other online services related to BSNL, we can go thro' below website address.
Find below the url for seeing the bsnl mail.