Hi,
What TorontoJoe said is about user management.
Yes RC si just a web mail client but each user using it, RC will store in the db. The user that is not in db can't use RC.
By default RC have auto_create_user = true so each time new user login for first time RC will store the user as a valid user in db.
However I am sure many user don't want anybody around the world use this their RC. It will eat their bandwidth (and space a little bit).
Consider my case, My office can't access gmail.com and mail.google.com because blocked by network admin. I use my own domain and RC connect to gmail via IMAP. Then I can access my gmail using my domain.
I don't want somebody use my RC. So I have set auto_create_user = false. However I also want my friends using this with my knowledge. What I want to do is change auto_create_user = true in mail.inc.php, upload, let user login, set to false and upload again or I need to add row in users and identities table in db.
I ddn't find the user management after googling around. My thougt RC not support it. However I believe this features is useful to many user.
LaNN