The Underscore Archives

After a recent post, I looked at campaign monitor... and it does appear to
be fantastic. However, I can't see any way of doing meta-lists (i.e. lists
made up from other lists). This is obviously a slightly hard thing to do,
especially when it comes to working out what people want to subscribe
to/unsubscribe from. Bear in mind our general advance listings elist is
currently made up of 15-20 different subcategories of people, so it's
unreasonable to expect staff to remember all the categories to tick when
sending out a list.

Are there any alternatives to campaignmonitor out there that are as good,
but do metalists too? Or at least, if someone visits the
subscribe/unsubscribe page, can see all the lists they're subscribed to (or
could subscribe to)?

Thanks,

Oliver.