Set up CAA

Having a CAA record in your DNS for Comodo, Let’s Encrypt won’t overwrite with a Let’s Encrypt certificate. Speaking in general terms, CAA secures for a correct certificate authority.

Explanation:
https://blog.qualys.com/ssllabs/2017/03/13/caa-mandated-by-cabrowser-forum

https://sslmate.com/caa/
Let’s Encrypt:
CAA     0 iodef “mailto:abuse@example.com”
CAA     0 issue “letsencrypt.org”

Comodo:
CAA     0 iodef “mailto:abuse@example.com”
CAA     0 issuewild “comodo.com”

DirectAdmin as name server:
Configure in directadmin.conf with dns_caa=1.