Why is this sentence wrong?

[Sherry Zhu]

A grammar book tells me this sentence is wrong. Does anyone know why? Thanks!

Enviamos mensajes de texto desde hace cincuenta años

[AngelicaDeAlquezar]

Except for the period at the end of the sentence, it seems correct. What is the context?

[ROBINDESBOIS]

Maybe llevamos enviado etc....

[aleCcowaN]

The only "mensajes de texto" I know are SMS, though the 50-year period is impossible (it's a factual error, not a grammar error)

I agree with ROBINDESBOIS that maybe the book isn't eager to accept the phrase as it is common but sounds the type you'd read in a headline or a sign. You may go:

Enviando mensajes de texto desde hace cincuenta años

that shows better the notion of continuity for a corporative ad, or

Llevamos cincuenta años enviando mensajes de texto

as "that is what we do" (Robin Williams will use a funny voice to add "Help us!")