ssl

ssl

Check certificate information

openssl x509 -text -noout -in

Check certificate at Dovecot
openssl s_client -connect <>:993 -showcerts

Run in order to check whether automatic certification renew process will succeed.

certbot-auto renew --dry-run
certbot certonly --dry-run --webroot -w /var/www/html -d domain.name
certbot --nginx certonly --dry-run

**Fix or issue**
Client with the currently selected authenticator does not support any combination of challenges that will satisfy the CA. #5415

Create certificate on debian when registering domain that differs from mail owner domain

How to create Lets encrypt certificate for Debian + apache + dovecot + postfix

We can download the certbot-auto Let’s Encrypt client to the /usr/local/sbin directory by typing:

Lets Encrypt