Let's Encrypt Integration Guide: https://letsencrypt.org/docs/integration-guide/
Rate Limits: https://letsencrypt.org/docs/rate-limits/
Let's Encrypt is running a trial for accepting rate limit adjustment requests from entities hosting large numbers of domains. Specifically, we are accepting applications from entities with the following needs:
1) Certificates for more than 500 subdomains of a particular domain. Note that only subdomains are rate-limited, so if you have a large number of domains which are not subdomains you will most likely not need a rate limit adjustment.
2) A very large number of domains for which issuance requires more than 300 pending authorizations at any given time.
If your use case is not described above please do not use this form.
We will do our best to consider your application in a timely manner but we cannot guarantee acceptance or any form of response, except that if your application is accepted and your rate limit is adjusted you will receive an email notifying you. We reserve the right to reject applications at our discretion, and we are not able to offer the ability to inquire about your application at this time. We hope to provide more transparency as this system evolves.