Odd mailbox problem

I use “catch-alls” on all my domains.
On one of them I have ONE “catch-all” mailbox configured (you know m********) and all email goes there and then I check it with Eudora.

Panel only show ONE mailbox configured for that domain.

BUT…I have a username for that domain that apparently has its own webmail account configured but it is NOT the “catch-all” one.

I accidently discovered this while using webmail and I just checked the webmail for that username and it let me in and I saw that I had mail there.
All email for that username is supposed to forward to the “catch-all” account, yet when I use webmail to check both accounts, identical emails show up in both accounts. When I use Eudora to check the “catch-all” account, one copy of the email is downloaded and the accounts are BOTH emptied.

So how is it possible to only have a single Email account configured for a domain (according to Panel), but still have an additional webmail account for another user? Its not really a problem, just an odd curiosity that I’ve found.