[horde] Can't create folder

[Leverett Litz]

I'm new to this and unsure what info you need to help me troubleshoot my
issue, so I'll start by posting the issue and then we can backtrack from
there.

I am using webmail in Horde and am unable to create new folders.  I want to
create a SPAM folder and make a rule to move SPAM to it.  When I try and
create the SPAM folder I get the following error:
The folder "SPAM" was not created.  This is what the server said:

That's it.  Can someone help me please create a folder in Horde?

Thanks for any assistance.