[exim] web based administration tools

Hi,
I run Linux as virtual server which serves 4 different domains. By default
we have to enter manually the domain and users in the /etc/exim directory.
So any open source web-based tools to do that? So that my clients can
administer their email users easy without interrupting the system
administrator each time an account is created or closed? Thank you for any
reply.


Regards

Willy