The change was made due to a rash of spam posts from vendors on extremely old threads. Now, while at first it just seems like a nuisance, keep in mind that we don’t have very much activity here so it’s not uncommon for a single post to generate a full set of digest emails (something like 400 emails). In addition, anyone who’s interacted with the thread will get an email with the full body of the post. All it takes for us is a couple spam reports and the Hotmail/Gmail users we worked so hard to get to the Inbox for will no longer receive our mail and we won’t have much in the way of recourse to restore it.
I’m certainly open to changing the policy, it was literally the quickest thing I could think of since I was heading out of town when I did it. But, that means we’re going to have to increase the delay before emails go out for site activity and people are going to have to start using the Flag Post functionality to prevent spam from going out.