Most specific zone selected by deepest sub-domain (how many '.' in the domain)
rather than seemingly irrelevant count of the number of characters within the zone.
This hook will copy the key and certificate chain to the specified
mailcow installation (as described in
https://mailcow.github.io/mailcow-dockerized-docs/firststeps-ssl/#use-own-certificates)
and restarts the containers, that are using the certificates.
The hook has 2 parameters:
* `DEPLOY_MAILCOW_PATH`: The path to the mailcow installation (required)
* `DEPLOY_MAILCOW_RELOAD`: The reload command, defaults to `docker-compose restart postfix-mailcow dovecot-mailcow nginx-mailcow`