Deleting Domain (Website / Mail / FTP etc) but Letsencrypt still acting on that domain

Hello,
I have removed a domain on one of my ISPCongfig servers (3.10, Debian 11). I deleted, DNS, Webmail / Mail / FTP etc. and Customer).
But when I look in the Letsencrypt log, it is still present within Letsencrypt and generates error messages on that domain (rightly of course, because domain was deleted and runs on a different server now).

How can I fix this now and prevent it in the future?

 

Indeed, ISPCOnfig does not remove the Let's Encrypt certificates when domain is removed. Find out which Let's Encrypt client you are using, and then on command line issue the commands of that client for removing a certificate.
You can see from the le client log what certificates it tries to renew, so you know what certificate name to use for the delete or revoke command.

 

As @Taleman said. As a note, there is a request to add LE certs deletion into ISPConfig feature so that may be possible in the future.