Email list Automatic Updater for Joomla and more...

I have a paid membership site. I need a method by which my clients, after logging in to the site can regularly subscribe or unsubscribe themselves from 9 different mailing lists. These mailing lists should always be up to date depending on the lists the members chooses.
Site is a Joomla site:
The subscribe/Unsubscribe page should look something like this:

Eur15min ( ) GBP15min ( ) Usd15min (*)
Eur4H (*) GBP4H (*) Usd4H (*)
Eurdaily ( ) GbpDaily (*) UsdDaily ( )

In the above example the user will be on all the lists with a "*" and not on the other. He can easily see his email subscriptions and change then anytime by simply marking or unmarking a tickbox.

THEN: I have other software, (already) that sends a email if a a signal happens in that software. I need this email to be read and depending on the subject text of the email, send a spesiffic email to one of the nine mailing lists.

Eample: Say software receives email with BGP15min as the subject text, a predefined email will then automatically and immediately be send to all the emails on the GBP15min email list. (Signals can happen up to every fifteen minutes, but mailing lists will not be very big, but should be able to grow as customer base grows.)

So in the end the following cycle should be fully automatic:
1. Member at anytime changes subscription in an online webpage.
2. If an email is received from signal Software its subject text is checked.
3. A predefined email is then send to all emails on that spesiffic list.

I have access to only one database(mySQL) that needs to be shared with joomla.