No idea how to troubleshoot Bugzilla email issue

I have a Bugzilla 4.2.4 install that is now unable to send email. It was able to send email without issue up until about a month ago (after about three months without issue). If someone posts a comment, a new bug or anything else that should generate an email, after they hit submit the following page takes forever to time out but eventually comes back with "Internal Server Error". Whatever they happen to be trying to do succeeds (bug gets created, file attached, comment posted, etc), so it appears that the problem is solely with generating the email. Following the [official guide](http://www.bugzilla.org/docs/3.0/html/general-advice.html) 's advice for troubleshooting I've created any errorlog but the output is nebulous at best: --------------------------------------------------------------------------- 06/03/13 13:02:02 global/code-error.html.tmpl mail_send_error 127.0.0.1 $env(ANSI_COLORS_DISABLED) = 1; $env(HOME) = "/root"; $env(LOGNAME) = "root"; $env(OLDPWD) = "/root"; $env(PATH) = "/usr/lib:/usr/sbin:/usr/ucblib"; $env(PWD) = "/var/www/bugzilla"; $env(SHELL) = "/bin/sh"; $env(SHLVL) = 1; $env(USER) = "root"; $env(_) = "/var/www/bugzilla/whine.pl"; --------------------------------------------------------------------------- 06/03/13 13:17:02 global/code-error.html.tmpl mail_send_error 127.0.0.1 $env(ANSI_COLORS_DISABLED) = 1; $env(HOME) = "/root"; $env(LOGNAME) = "root"; $env(OLDPWD) = "/root"; $env(PATH) = "/usr/lib:/usr/sbin:/usr/ucblib"; $env(PWD) = "/var/www/bugzilla"; $env(SHELL) = "/bin/sh"; $env(SHLVL) = 1; $env(USER) = "root"; $env(_) = "/var/www/bugzilla/whine.pl"; I've verified that SELinux isn't the issue by switching it into Permissive for the full duration of this troubleshooting, and I've created simple perl scripts that send my personal email account when invoked over Apache httpd. httpd's error_log doesn't have anything too interesting for this error: [Wed Jun 12 13:21:20 2013] [warn] [client 152.xx.99.118] Timeout waiting for output from CGI script /var/www/bugzilla/post_bug.cgi, referer: http://bugs.xxx.edu/enter_bug.cgi?product=Banner%20INB [Wed Jun 12 13:21:20 2013] [error] [client 152.xx.99.118] Premature end of script headers: post_bug.cgi, referer: http://bugs.xxx.edu/enter_bug.cgi?product=Banner%20INB Basically, I'm unsure where to take it from here, I don't know how to get Bugzilla to give me more descriptive error information. I know that administratively I didn't change anything, there's plenty of processor time and storage space available, so I'm not sure why it all of a sudden broke. This is on a RHEL5 machine with Perl 5.8.8