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Two values should be changed:
1.
- Go to WHM -> Tweak settings -> click on Mail Tab -> find "Max hourly emails per domain" and set number you need.
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- 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.
That's all.
If you have shared or reseller hosting package, limits can be found here: Email Limits - How many emails per hour?
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