There is one very important list setting missing: the ability to set the limit of messages per subscriber send in a specified time period (setting applicable per list or subscriber). For example - send no more than 2 emails per subscriber per week.

For example – we have our list segmented into very narrow segments based on the types of products customer buy. We are planning to send 5 targeted mailings per week into different segments of the whole list – however it can happen that one subscriber appears in all 5 segments of that list (frequent buyer). We don’t want to annoy such subscriber with all 5 mailings send to him day by day. We want to send no more than 2 emails per the same subsciber per week. So when he receives first 2 emails, the rest of the emails send to the segment he's in won't be send to that subscriber any more.

The limit of emails send per subscriber could be set globaly on the list level or individually on the subscriber level. 12all admin or even subscriber himself (on the preferences setting page) would have a possibility to set the time period for this limit (in days) and the numer of maximum emails that should be send to him (subscriber). For example "send no more than X broadcasts in the period of Y days".