Nagios Support Forum

@tgriep is right, and some plugins have a -t parameter for you to specify a timeout.

Thanks,
I have increased by 5 seconds the plugin timeout option.
I have adjusted the service_check_timeout value to be greater than 5 seconds compared to in built plugin; hence Nagios will kill the plugin before the plugin itself and exit UNKNOWN (which will not notify via email).
I think I will apply the change for all my checks and cut the amount of alert sent out regarding plugin timeout states.
I am happy to set this post as resolved.
Thank you all for your help.
Regards

Sounds good, I will mark this post as resolved and close it out.

Feel free to open a new one if you need assistance in the future.