This program is a free SMS messaging system.
The premise is that you must log in to mail.139.com, find "My Mobile Phone", find "Register New Service" and enter your mobile phone number. This is a free service provided by China Mobile.
Have to use a mobile mailbox. Register an account at mail.139.com. Then send this email to your own mailbox. For example, your registered email address is
[email protected], then fill in your mobile phone email address as
[email protected], and there will be text messages on your phone.