Keeping your brand consistent across user touch-points is important to modern Saas companies. Just like customizing Login Pages, customizing your email templates is just as important. Keycloak has a number of templates which can be customized.
Keycloak starts out with simple text templates, but unless you like spending your days looking at Unix terminals, you probably prefer some color and images in your emails.
Email is one of the highest touch-points for users with your application. Being able to configure and customize emails is key to user management and experience.
One of the first things you will need to do when getting a Keycloak Realm ready for use is to set up your email server configuration. There are many system emails that are sent to users in the course of verifying and updating user accounts: Email address verification, magic links, password reset, account update, login failure notifications, identity provider linking, etc.
In order to provide your users with a positive experience, these messages need a way to get to them. Keycloak supports any internet reachable SMTP server. If you are currently testing, and don't have an email server or service that you currently use, SendGrid provides free accounts that allow you to send up to 100 emails per day forever. For debugging, you can also use a service like MailTrap to give you a catch-all for emails coming from Keycloak.