SSL Rate Limits
When you enable SSL on a site, we use certificates issued by LetsEncrypt.
As with most web services, LetsEncrypt has rate limits to prevent abuse and DDOS attacks. You should be aware of these limits because they can affect whether or not you’re issued an SSL certificate for your new sites.
Notable limits are:
- 5 new certificates for the same domain every 7 days. This limit is the most common trap that trips admins up. If you continually try to issue an SSL certificate because you’re getting an error you will quickly run into this limit. Once you hit this limit you’ll have to wait 7 days to attempt to issue the certificate again.
- There is a Failed Validation limit of 5 failures per account, per hostname, per hour. Continually attempting to issue an SSL certificate because you’re getting an error will quickly run you into this limit – if you encounter it you will have to wait 60 minutes before trying again.
- There is a limit of 50 subdomain certificates every 7 days. So, if you have an top-level domain such as mydomain.com, you can only have 50 subdomain certificates of the format subdomain.mydomain.com issued per week. If you’re selling site subscriptions you might hit this limit if you’re selling more than 50 subscriptions per week.
You can view all limits here: LetsEncrypt Rate Limits