The Mail screen is used to provide information on your SMTP server. This is required to distribute Stories periodically via email.
Note on OAuth 2.0 usage
Usually OAuth tokens have a very short lifetime (from hours up to days). This means the configured SMTP token (password) must be updated/rotated often. Doing so through the UI is inconvenient.
For such cases CPM4 exposes SMTP Authentication API. This HTTP API could be leveraged by automated scripts. Please see our API specification document for more information.