In order to send messages in Stello you'll need to create a sending profile.
Sending profiles consist of...
1. A sending account
Stello uploads encrypted sent messages to a server so recipients can read them and also saves encrypted responses there until Stello is opened and downloads them. So in order for Stello to function you must have a sending account.
Gracious Tech (Stello's creator) provides free accounts to make Stello easier to setup.
2. A connection to an email account
Stello must be connected to an email account which is used to both send messages and receive notifications. Stello only ever uses your account to send messages and never reads them from your account.
You can use the same email address for multiple sending profiles and can change it at any time.
3. Settings for messages and responses
Most settings in Stello are specific to a sending profile, so you can have different settings per profile.
When someone unsubscribes from your messages the unsubscription only applies to the sending profile that was used, so you should use different sending profiles for different newsletters.