This would do a couple of things...

1. Conserve server resources sending messages to people long after the thread has been forgotten and the email pretty much ignored.(Probably stop a lot of bounced emails too.)

2. Simplify account housekeeping...

Make it available to delete subscriptions after a number of days(selectable). Say delete all subscriptions were the last message is over 30, 60, 90 or 180 days old or never.

Just a thought while I was getting rid of old subscriptions.

Thanks for the suggestion.