I'm using PHPMailer to send out site contacts.
In development, the script works perfectly with the GMail service over smtp. However, in production, inside the client's DMZ, it appears unable to connect to the SMTP service they have there. I have connected to the same service using telnet to port 25, so I know for sure it exists and is available to the server.
Are there any circumstances where php might not be able to open a socket connection (fsockopen)...? The php extension openssl is loaded and ok.
The error is "Unable to connect to SMTP service".