In especially bad news for those who try to reach Inbox Zero, Substack had a problem today that sent out some of the platform’s newsletters for a second time. Verge contributing editor Casey Newton noted it sent out a second copy of the free edition for his Platformer newsletter (which you can subscribe to here), and several of us have seen additional copies for some of the emails we subscribe to in our inboxes.

Substack co-founder Hamish McKenzie tells The Verge it was a “one-off bug.”

It’s unclear exactly how many emails were mistakenly duplicated, but the company explained things a bit more in a tweet, saying “A recent update triggered duplicate emails for a subset of writers’ email lists. We apologize for the inconvenience to you and your readers. We’re on it, and we’ll make sure it does not happen again.”

Of course, if you just missed the last edition of The Kicks You Wear in your overstuffed inbox that is never at zero, getting a second copy is more of a helpful reminder than an annoying extra message. And if you’re troubled either by missing a subscription newsletter or receiving one copy too many, the still-in-beta RSS reader or mobile app (iOS only right now, there’s a waitlist for Android users) can provide some alternate options.