What does it mean for prisoners to open a temporary text messaging platform?

After opening the temporary text messaging platform, you can send text messages to your family members.

Prisoners are generally not allowed to send text messages, but in some places they can send family text messages after review. According to management regulations, in addition to correspondence, the only way for prisoners to contact their families is through phone calls. Correspondence takes a long time, and many inmates in other places often have to wait a week to receive letters from their families. The family phone calls are only open to inmates with better performance. Prisoners do not have mobile phones and cannot send text messages at will. Some places have opened "family text messaging platforms" to report good news but not bad news as much as possible, and the content sent must be reviewed.