Yesterday we received a notification that we need to renew a certificate for a specific domain (cluster.ziyu.cl) as it will expire in 6 days.
Reviewing our settings we have confirmed that we do not have this domain in our records. Could you please confirm what this message is for or where did you get the information for that domain? Thanks in advance.
Someone got a cert with that domain name on Nov24. Actually, two certs (see link here). They must have used an ACME Account that was setup with your email address. UPDATE: Corrected "see link" to crt.sh thanks @rg305
Some services get Let's Encrypt certs on your behalf without you knowing. Such as when proxying your domain at Cloudflare it will get a cert for use at its CDN Edge. Other CDN's and even hosting services may do this too.
If you are sure you do not use this cert then just ignore this friendly warning email. This is the last email you will see about it.