To answer your question, a competing control panel named Plesk uses Qmail!
More information: http://www.swsoft.com/plesk
Personally I don't think Plesk is as good a control panel as Cpanel and is
lacking a lot of features. The company where I work used to be
100% Plesk based but we converted everything over to Cpanel
about a year ago and have been much happier on Cpanel.
Is there a specific reason why you want to use Qmail?
There is two ways that you can setup the mailboxes with Cpanel and Exim ....
One way is to use a mailbox file (mbox) for email account and the other
preferred way is to use a set of directory folders for mail (maildir). The
second method I speak of is virtually identical to how Qmail operates.
We have all of our Cpanel servers configured with the newer maildir
configuration and it operates EXACTLY like Qmail. I personally have
a great many years experience with Qmail and I'm right at home in