Error when generating cert for customer: Policy forbids issuing for name

Hey!

I work at ReadMe (a hosted documentation platform), and we generate SSL certificates on behalf of our customers using Let’s Encrypt https://blog.readme.io/auto-generating-ssl-certificates-for-custom-domains-using-lets-encrypt/. One particular customer’s certificate is not generating and is returning with the following error:

Processing
 + Signing domains...
 + Generating private key...
 + Generating signing request...
 + Requesting authorization for...
 + ERROR: An error occurred while sending post-request to https://acme-v01.api.letsencrypt.org/acme/new-authz (Status 400)

Details:
{
  "type": "urn:acme:error:rejectedIdentifier",
  "detail": "Error creating new authz :: Policy forbids issuing for name",
  "status": 400
}

This appears to be a similar error to this one here: Policy forbids issuing for name on Amazon EC2 domain. The customer is a fairly well known company with a domain that is presumably on the blacklist. What’s the process for getting an exception for this list?

Thanks!
Dom

If it’s blocked due to being a high risk domain, the customer can try emailing security@letsencrypt.org .