I cannot send mail with SwiftMailer or PHPMailer from Localhost using gmail - email

Question

I have recently been unable to send out mails through php on localhost. I use PHPMailer and SwiftMailer in different parts of the application.
With SwiftMailer I get this:
Connection could not be established with host smtp.gmail.com [ #0]
With PHPMailer, the message is:
SMTP Error: Could not connect to SMTP host.
My settings on SwiftMailer look like this:
$transport = Swift_SmtpTransport::newInstance('smtp.gmail.com', 465, 'ssl')
->setUsername(APP_GMAIL_EMAIL)
->setPassword(APP_GMAIL_PWD);
I have gone through several threads here at SO and elsewhere, and tried many 'fixes' but the error messages remain the same. Some "solutions" I've tried are:
Enable OpenSSL inphp.ini (It was previously off)
Change smtp.gmail.com to smtp.googlemail.com
Replace smtp.gmail.com with certain gmail IP addresses
Replace smtp.gmail.com with gethostbyname('smtp.gmail.com')
Add ->setSourceIp('0.0.0.0') to the instantiation code above, after setUsername and setPassword
This code was previously working, and I'm not sure what could have broken the function. As part of troubleshooting, I have just confirmed that a similar code on Linux shared hosting is emailing satisfactorily, suggesting that the problem is somehow from my environment. Thus, I even tried different sources of internet access, in case it's an ISP thing.
How can I crack this nut?

Answer 1

I have been able to overcome the problem, at least with SwiftMailer. The solution must have arisen after my PHP upgrade from 5.2.5 to 5.6, which is the version I have currently. The insight came from this page:
https://github.com/swiftmailer/swiftmailer/issues/544
If you are using PHP 5.6, the error does occur because of the "SSL
context options" used for the stream context in swiftmailer. IN PHP
5.6 verify_peer and verify_peer_name the default was set to TRUE, so PHP checks the SSL certificate. It is currently not possible to
disable it in swiftmailer using some options.
You could disable the SSL check by modifying the function
"_establishSocketConnection" in StreamBuffer.php. Add these lines
before stream_socket_client command:
$options['ssl']['verify_peer'] = FALSE;
$options['ssl']['verify_peer_name'] = FALSE;
It would be great if these options could be set without hacking the
code.
Thanks to https://stackoverflow.com/a/29448735/2554788 who first pointed me to the said post.
By the way, the path to StreamBuffer.php is:
\lib\classes\Swift\Transport
A word of warning though: this solution is based on hacking the code inside a class, and will probably fail, say, after upgrading SwiftMailer versions (in which case you'd need to go back and hack the code again).
Perhaps, more current versions of SwiftMailer have put their acts together in PHP 5.6 (I use SwiftMailer 5.1 currently). I intend to try an upgrade ASAP, hoping there has been an elegant fix for this issue.