Outlook:Deleting mailboxes- still there during send/receive

I've deleted a mailbox from outlook because of some problem with the mailbox. However, when I send/receive, the mailbox still appears in the mail server list. I've since re-added the mailbox, but now there is yet another mail server in the send/receive list. What am I doing wrong? How do I properly delete the mailbox from outlook, and then I can address the issue of the original problem with the mailbox.

I fixed the problem by renaming the mailboxes, ensuring there are no name conflicts.