For some bigger-picture context, you may be interested in this help page, which explains our order-handling process in layman's terms using familiar real-world analogies:
The issue yesterday was entirely at PayPal's end. E-junkie's system was working normally the entire time, during which we continued to process orders paid through other payment services such as Google Checkout or Authorize.Net, or even card-based direct payments using PayPal Advanced/Pro that didn't go through PayPal's checkout site. We simply weren't receiving any payment confirmations from PayPal for orders paid through their checkout site, so those were the only orders affected.
We depend on receiving IPN (Instant Payment Notification) from PayPal to confirm when their checkout site has completed payment for a given order, so we can then process that order for you (issue links, send emails, log the order details); this normally happens almost immediately after the buyer finishes checkout. However, if we don't receive IPN for an order, our system has no way of knowing that order was actually placed and paid-for.
Early yesterday morning (shortly after midnight MST), PayPal's system started having some issues, or possibly one major issue with diverse side-effects, one of which was that their system stopped sending IPNs to anyone, including E-junkie. PayPal resolved their problem yesterday afternoon, at which point we started receiving IPNs for new payments almost immediately (as usual), and they started catching up with sending the backlog of IPNs that were delayed as a result of the problem, so our system resumed processing orders for both new and delayed IPNs as they rolled in from PayPal.
This service status posting on PayPal's developer site gives a timetime of updates (from newest to oldest) regarding this issue as it developed and was resolved; these are probably all the details they're going to provide on this matter:
PayPal posts notices of known issues at their end on their developer site's Live Site Status page here:
If you happen to use PayPal Advanced or PayPal Payflow Pro, issues specific to card-based payments with those services are posted in their Gateway Live Status page here:
Whenever we are aware of an issue affecting our system, we post notice to our Service Status & Updates subforum here:
If you're into RSS, you can subscribe to a live feed of our System Status & Updates subforum via this URL:
I've asked Development to consider the mass-email notification suggestion. Our Twitter feed and Facebook page are managed by our Marketing team which doesn't have their pulse on the technical side of things, so we've obtained access to those social media accounts and will be able to post service status notices there if necessary in the future.