Recently, I set up a telecom calling card, one of which is Tianyi 189 mailbox. Is it different from other mailboxes?

Tianyi 189 mailbox is a mailbox that all Tianyi users can register, which supports most of their own mailbox functions, but it also has some features of its own, such as mail collection, automatic forwarding, alias setting, SMS reminder, self-written SMS (300 messages are given every month, and 50 messages can be sent free of charge every day), and there is 2G space for activating the mailbox.