[exim] Looking for Seggestions to Personalize settings using…

Here's what I have in mind. Per user customizations allowing people to
set things like their own white lists and black lists. The idea being
that a user sends a message to a control address like
control@???. In response the server looks at the from address and
sends an email back to the users with that users current setting and
instructions about how to change the settings. The use would the reply
to the message with the desired changes and the server would make the
changes sending out a confirmation.

Sounds fairly straight forward but it would require some reasonable
security so that it isn't easilly intercepted and spoofed. The reply
message would probably have some sort of access key that is good for a
limited period of time.

I'm looking for some feedback on this idea and perhaps people who might
want to develop this with me. I have a lot of the backend written using
Exim ACLs that I'm willing to share. My version is driven by flat text
files but maybe a MySQL version would eventually be better.

Thoughts?