Resolved.

On Sunday August 17th, 2025, between 2:15pm and 1:30am Eastern Time, sending emails through Buttondown's markdown and fancy mode editors often failed. This did not affect emails sent through the Buttondown CLI, Automations, RSS-to-Email, or the Buttondown API.

This manifested as a perpetual "Loading…" screen after pressing "Publish," and the email not sending.

This was due to a bug fix that was rolled out in the afternoon. Changes are not frequently made to Buttondown's code on weekends, but this change was degrading some customers' ability to write in the editor, so we verified that the fix was valid and rolled out the change.

However, this change introduced a bug: immediately after an email's status was changed to about_to_send by an author pressing "Publish," our editor would mistakenly detect that it should be set back to draft. Therefore, most emails were put into about_to_send and then subsequently pulled back to draft.

Unfortunately, because this change was made on the weekend and our support operates Monday-Friday, we did not notice customers flagging the issue to support until the evening. We identified the issue and rolled out a fix around 1:30am Eastern Time.

We take such incidents, especially to major core functionality, extremely seriously. We apologize for anyone who ran into this issue, especially with time-sensitive emails that were delayed.

Going forward, we're preventing an incident like this by adding a monitor that pages the team if an unusually low number of emails has been sent recently, and by adding end-to-end tests that automatically test email sending from the editor.

If you have any further questions, we'd be happy to answer: support@buttondown.com