I have downloaded plugins from Nagios Exchange, such check_email_delivery. After download I copy the files to my /usr/local/nagios/libexec directory, set up the command in commands.cfg and then set up the check in the relevant *.cfg file.
However, the checks work fine from the command line, but when they run from inside of nagios all I see is "unknown" and text that tells me what that command should be.
The same command that runs fine from the command line.
All plugins that were installed as part of the Nagios-Plugins install work fine.
How can I fix this on my Ubuntu 11.04 system?