Expertise level: Advanced
It is possible to tweak IMAP and POP3 services on your server in order to change the maximum number of connections to your server. These changes should only be made by experts, as misconfigurations could have negative effects on your mailing system.
Start by logging into WHM as root.
Open the "Server Configuration" menu.
Click on "Mailserver Configuration".
You can make desired changes in the configuration. When you have completed your changes, be sure to click "Save".