How to send text messages in mobile phone mailbox?

Unicom's mobile phone mailbox service is a mailbox service provided for mobile phone users through fixed or mobile Internet. By default, the mobile phone number is used as the mailbox user name, which has the function of real-time notification of mail arrival. You can send and receive, view, reply, forward and manage emails and attachments through your computer or mobile phone.

Unicom's mobile email does not support sending short messages for the time being.