Why did you receive a message from a fixed line? Under what circumstances can a fixed line send a short message?

PHS, or information desk, now has some methods to hide or change the sender's number. Some scammers will use it, so be careful. In addition, it seems that some rural areas have launched mobile phone card business, which can bind their own landline and then be equivalent to an extension. The number and phone bill are bound to the landline. It is estimated that if you can send a text message, the fixed-line number will be displayed.