Error on sending email test

Hi,

I’m having problems sending emails using the WP Contact Form 7.
I’ve installed the WP Mail SMPT plugin to test, and I have the following errors:

Versions:
WordPress: 4.9.4
WordPress MS: No
PHP: 5.5.38
WP Mail SMTP: 1.2.5

Params:
Mailer: mail
Constants: No

Server:
PHP.mail(): No

Waiting for an answer,
Thanks.