Swift_TransportException Connection could not be established with host smtp.gmail.com [Network is unreachable #101]

Some months ago, I used gmail setting in my .env file,

MAIL_DRIVER=sendmail
MAIL_HOST=smtp.gmail.com
MAIL_PORT=587
MAIL_USERNAME=myEmail@gmail.com
MAIL_PASSWORD=myPassword
MAIL_ENCRYPTION=tls

It was working perfectly fine. But suddenly it stopped working. Now, it is showing an error, which is:

ErrorException (E_WARNING) proc_open() has been disabled for security reasons

What's going on?? I have tried all the methods found on internet but didn't worked. Did Gmail got any new security system?

I have tried changing,

MAIL_DRIVER=sendmail to MAIL_DRIVER=smtp

But getting below error,

Swift_TransportException Connection could not be established with host smtp.gmail.com [Network is unreachable #101]

via Chebli Mohamed