The change has been reverted, and subscribers have been restored to their correct status.

There is no action required from authors.

There was no impact to subscriber-facing features.

The change is still being reverted, but we expect that this will be complete shortly.

Please continue to refrain from sending until the fix is complete.

The Buttondown dashboard and API are mistakenly marking subscribers as undeliverable.

We're in the process of reverting the change.