xmera Omnia

The configuration.yml reads the env vars given in env.yml. By doing so, some env var values needs to be transformed to a Ruby symbol what will be done like so: <%= ENV['EMAIL_DELIVERY_METHOD']&.to_sym %>

However, it turns out, that this transformation is not enough. Additionally, a colon is necessary: :<%= ENV['EMAIL_DELIVERY_METHOD']&.to_sym %> to make it work.