For some reason, for almost every Newsletter (like 99%), NewsBlur starts a new “feed” every few weeks (or some interval), and then does so again after a similar period—ad infinitum. Therefore the list of feeds in the Newsletters folder expands continuously.
I’ve checked the actual URL that is used (in case it changed but was still picked up by NewsBlur) many times, and that’s not the reason (the URLs are identical). So what makes NewsBlur suddenly and arbitrarily start a new feed? In each case, the “new” feed is the one that appears to be active, because the “old” one(s) are empty of articles (or no longer appear). In some cases there are 4 feeds for the same Newsletter.
I’ve uploaded a screenshot of a good example of the problem, which left unchecked, will eventually defeat the purpose of Newsletters