Temporary failure in name resolution

[avanzi]

Dear , I do not understand what happens. I set up the sending of emails correctly, but it seems that the DNS does not resolve the name of the mail server ( smtp.gmail.com ) . There is nothing wrong with DNS's on my network . The funny thing is that when I change the email service to PHP Mail ( ) function, the message " successfully sent " is generated but the email does not arrive in my inbox . The images are attached. Error message : "Unable to connect to SMTP Host ' smtp.gmail.com ': ( 0) php_network_getaddresses : getaddrinfo failed: Temporary failure in name resolution " . can you help me ?

[BSOD2600]

reviewed https://support.google.com/a/answer/176600?hl=en ?