Bug text translation for the submit button

Hello,

Must have a problem the Contact Form 7 plugin v.4.0.3 because there is no way to make the Spanish text of the submit button translation [SEND MESSAGE!]. We’ve tried several ways, such as eg. inserting the HTML:
<p> [submit "ENVIAR MENSAJE"] </ p>

even entering:

<p> [submit " "] </ p>

message [SEND MESSAGE!] continues to appear 🙁

How can we make the translation if not the
phrase “SEND MESSAGE!” in .POT file?

Regards

https://wordpress.org/plugins/contact-form-7/