If you have a dedicated server or a VDS, you might want to change emails per hour limit in case you need to send newsletters to many recipients. By default this number is set to 250 emails/hour, so in case one of your accounts is hacked - it can't send tons of SPAM. So, once you decide to change this limit, please be careful.
Two values should be changed:
- Go to WHM -> Tweak settings -> click on Mail Tab -> find "Max hourly emails per domain" and set number you need.
- Go to WHM -> ConfigServer Security&Firewall -> click on "Firewall Configuration" button -> press "CTRL+F" and find "LF_SCRIPT_LIMIT"
Set the values that you need.
If you have shared or reseller hosting package, limits can be found here: Email Limits - How many emails per hour?