The maximum number of certificate requests has been reached

[KJS]

Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. https://crt.sh/?q=example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.

My domain is: kjshh.selfhost.eu

I ran this command in my Synology DiskStation: “Get a certificate from Let’s Encrypt”

It produced this output: 1. "Invalid e-mail address"
and subsequently with a different e-mail address: 2. “The maximum number of certificate requests has been reached for this domain name.”

My web server is (include version): ./.

The operating system my web server runs on is (include version): ./.

My hosting provider, if applicable, is: Selfhost.de

I can login to a root shell on my machine (yes or no, or I don’t know): I don’t know.

I’m using a control panel to manage my site (no, or provide the name and version of the control panel): ./.

How can I receive a certificate after this error message without having to change my domain?

Thanks in advance
KJS

[Patches]

@KJS

“The maximum number of certificate requests has been reached for this domain name.”

Your hosting provider hasn't listed selfhost.eu on the Public Suffix List, so it is treated by Let's Encrypt like any other private domain and certificates for it are limited to 20 per week excluding renewals.

You should contact your hosting provider and request that they add their domains to the Public Suffix List. This has several security benefits for dynamic DNS providers in addition to moving the rate limit level up, like preventing other customers from setting cookies on your domain.

If for some reason they do something weird and can't be listed on the Public Suffix List, they could also seek a rate limit extension from Let's Encrypt. But the PSL should be their first option.

@KJS

How can I receive a certificate after this error message without having to change my domain?

Keep trying and eventually you'll get lucky.
Sometimes we can calculate when the next slot will open up but there are too many certificates and renewal exemptions going on with this domain to do so easily.