Generally, installing from source (see section `Source Installation from Git`) leads to a better experience using Certbot and Let's Encrypt, especially if you're using an older OS release.
The email address used to agree to Let's Encrypt's TOS and subscribe to cert-related notifications. This should be customized and set to an email address that you or your organization regularly monitors.
By default, this role configures a systemd timer to run under the provided user every day. The defaults run `certbot renew` (or `certbot-auto renew`). The account used should be a non-root account.
Services that should be stopped while `certbot` runs it's own standalone server on ports 80 and 443. Other valid values might be `apache2`, or any other serivce that might use these ports.