Is it cheaper to send text messages or emails by mobile phone?

Sending a text message costs telephone+electricity (cell phone battery)+cell phone depreciation.

E-mail fee, electricity fee, broadband fee and computer depreciation fee.

It seems that the cost of sending text messages is similar to that of sending emails.

But it depends on reality.

SMS is more timely than email. ...

I think email is really cheaper than SMS.

E-mail from mobile phones consumes mobile phone traffic ... that e-mail is much cheaper.