A web server that has successfully sent mail using the hosting providers's SMTP server before seems to suddenly have lost connection to the SMTP server.
[Wed Nov 28 09:51:27 2012] [error] [client 10.250.11.81] PHP Warning: fsockopen(): unable to connect to smtp.ourprovider.net:25 (Connection timed out) in /var/www/(....)/phpmailer/class.smtp.php on line 105, referer: http://oursite.net/sendmessage.php#
If I telnet to the SMTP server's port 25 manually from the web server, I'm able to connect and send mail with no problems whatsoever.
The web server is running RHEL 6.3 and Apache 2.2.15. The SE boolean
on. Our PHP version is 5.3.3.
Where should I start looking to fix this?