[RoundCube Users] unwanted INBOX.Drafts INBOX.Sent INBOX.Trash folders

Hello

I'm quite a newbie but I've managed to install Roundcube without any problems, everything worked first time. The only thing is that there are three folders in the folder list that have appeared and I don't know what they are:

INBOX.Drafts INBOX.Sent INBOX.Trash

These are in addition to the normal Sent and Trash folders. I've noticed that they also exist in Neo, Horde & SquirrelMail that my hosting company (Quality Host Online) provides.

What are these folders, and is there any way to get rid of them, as they seem to be unnecessary?

Thanks very mush Simon