ConfigServer makes your life as a WHM user / sys admin much more easier!
The product provides you with an interface to the cPanel user accounts email configuration without having to login to their accounts and it's also domain based rather than account based tool.

Here's a list with what you can achieve with this tool.

View, edit and delete email accounts
View, edit and delete email forwarders
View, edit and delete email filters
View and modify email account quotas
Modify email account passwords
Modify Outgoing Mail Hourly Limits
List only email accounts that are over quota (or over a specified percentage)
List only email accounts that are over a specified size
View the total number of emails in an email account
Empty an email account
View emails in an email account
Individually delete emails in an email account

How to install cmm

cd /usr/local/src
wget http://download.configserver.com/cmm.tgz
tar -zxvf cmm.tgz
cd cmm
./install.sh