i too got messasge like you but i was confused.
but after checking i found that the account is from post office savings account i am not saying all are fraud or all are correct like mine
please check if you have any saving/RD or any type of accounts in post office.
as from pas few years post office banking has also been improvised and updating their customers via SMS service.
from my side i will say i did not got this message unintentionally.