If groups were sets, I could assign people to multiple groups, and send a mail to e.g. all the women in oregon, where 'women' and 'oregon' are groups, and my mail would go to the intersection.  Or a mail to all my customers who do not receive the newsletter (the set difference between 'customers' and 'newsletter', thus avoiding mailing people twice).

And some groups would have intensional definitions, e.g. 'usa' contains 'oregon'.  If I add an address to 'oregon', it would automatically receive mails sent to 'usa', without me having to add every oregon name to the group 'usa' by hand.

I think this would provide a very powerful yet simple (to code and to use) system.

Is this possible, or is there any plan to provide this?

Greetings,

Biep.

P.S. 1: I post this to the mail forum, but I guess the feature would be useful elsewhere as well.

P.S. 2: Maybe I am using the wrong terminology - when I say 'groups' I mean distribution lists or categories.