Legal cyrus mailbox names?

[James Yale]

Hi,

I'm trying to figure out what I can actually have as a valid mailbox 
name in cyrus, due to problems with mail being delivered to the wrong 
account.

I realise I can't have any '.' in the name, but currently mail for user 
'jim+test' (who can login just fine) is being delivered to user 'jim' 
instead.

I've also seen people suggesting that mailboxes can be user at domain.com, 
but I get permission denied whenever I try and create a mailbox in that 
format.

Any suggestions/links to good documentation would be appreciated :)

Thanks,

Jim
jim at thebiggame.org