Hello, I am trying to determine the best way to limit who my users can email. I am using a Redhat/Squirrelmail/Dovecot/Postfix configuration. I have 3 categories of users, and each category has a separate "address book" in Squirrelmail, and I need to limit who the user can send mail to the addresses in their classes address book.
I programmatically generate the 3 address books, so I can easily create the files in another format more friendly to Postfix. I believe I need to create 3 classes of users in Postfix, with each class having their own list of valid recipients they can email. The tests in Postfix would first determine which class the sender was in, and then determine if their recipient was valid. I'm dealing with 3 classes of about 1000 users, with each class having about 100 valid addresses to choose from. I am guessing I should use hash tables instead of regular expressions, so it would be faster. Does this sound like the right approach? The email load on the system is pretty light (about 3000 emails a day).
