API traffic from Plesk is blocked

We've temporarily blocked traffic to our issuance API from Plesk installations. This is an emergency measure: we saw a sudden, very large spike in traffic (polling the status of authorizations) from thousands of independent Plesk installations that is above our capacity to handle. We've reached out to Plesk to try to figure out what's going on and stop this traffic, so that we can get this resolved for everyone ASAP.


Update: We unblocked traffic from Plesk the day after this.