Starship Server users are the only choice if you are installing server on Linux. On Windows, choose this option, if the machine where you are installing server is a standalone server, not part of any domain. This is also a better option if you have a lot of Mac or Linux users.
If you chose Starship Server users during installation, you then have to create user accounts.
To add more users, go to Administration -> Users and click on Create user.
When you create a user you get an activation link, which you can send to the user. Activation link allows the user to choose his/her own password and then use the account to login or send data with Starship.
You can also copy activation link and paste it into a browser window to set the password.
User can then use the same username and password to send data from Starship.
In Administration -> Email you can setup an email account, which Starship Server uses to send emails. When account is correctly configured, you can also send activation links via email.