Can't I send a text message without a mobile phone number?

It's just that the short message you sent has been running in the background of the mobile phone and can't be sent out.

But as soon as your mobile phone receives the signal, it will send it out immediately.

(Note that different brands of mobile phones have different background running times. MOTO's is 24 hours, and Nokia's is set to 1 ~ 24 hours according to the mobile phone. )

That's all I know