Purging older (unread) articles...

[barcaroller]

Is there a setting in Vienna to ask it to purge (read and unread) articles that are older than a specified period (e.g. 7 days)? Currently, the only setting I could find purges only read articles, which causes an accumulation of (what seems) an unlimited number of backlogged unread articles. Having such a setting would also have the additional benefit of purging articles that have unusual/strange timestamps (like January 1st, 1970).