There should be a setting in WHM that says Tweak Settings. Go there, then go to Mail. You should see a field called "The maximum each domain can send out per hour". Just change the number to what you want the limit to be (0 is unlimited)
The problem with the above method is that it only works on mail sent via SMTP — doesn't on mail sent via PHP scripts. There is a workaround, though. In WHM, go to Security > Security Center > SMTP Tweak. That will force users through your SMTP server.
|