Yes Upadhyay.kamal is right, I used to have this plugin in one of my blog and after using for few days I received email from host saying my blog is using too much resources here is the email body:
After disabling the plugin everything went back to normal. I know this is the best plugin but developer needs to work on lessen the database queries.
Resource usage notification: xxxx.com
After some recent problems with the server xxxxxxxx.com we found that your site xxxx.xom is causing some issues due to your site's resource usage. Your site is using too many system resources (CPU and Memory) for shared hosting. With shared hosting you are sharing the hardware resources with other people and unfortunately your site is using more than it's fair share.
Here is a summary of your CPU and memory usage on your account over the past 24 hours:
We believe the processes shown below are responsible for this level of resource usage, please keep in mind if you run a dynamic site off WordPress or another script it might just show index.php which is the primary file that runs the entire site:
Top Process %CPU 108 /usr/bin/php /home/xxxx/public_html/wp-admin/admin.php
Top Process %CPU 97.3 /usr/bin/php /home/xxxx/public_html/index.php
Top Process %CPU 87.5 /usr/bin/php /home/xxxx/public_html/index.php
Your website still remains active, but our techs might have to disable it if it increases or causes further problems. Because resources are shared, I'm sure you can understand that we need to take action if one site is causing downtime for dozens of other sites.
We would also like to apologize, we are working very hard on getting CPU graphs directly to customers in their control panel so our customers can see when their site is starting to use too many hardware resources for shared hosting. This is something that happens very rarely and only 1% of our customers ever have a site that is using enough resources to cause this level of problem. If you have any questions please don't hesitate to ask.