Mistake while setting up mailbox

[Stefan Fricke]

Under cyradmin you create a mailbox with

cm user.username

But I accidentally did cm username

Afterwards I tried tio correct it by doing the correct statemend

Now there are the mailboxes username and user.username which seems to blok 
user login.

I tzried to delete the accidentally created mailbox but

sam username cyrus cd

causes an I/O error.

What can I do?