IMAP - Quota ?

[green_man]

I have some questions for the administrator types about IMAP.
I have an IMAP account at netscape.net that I use for several user 
forums and mailing lists, and it was recently *HOSED*.
All of my saved messages, subdirectories, mail filter rules, etc. are 
gone when I opened it.
Only my address book and initial directories [inbox, sent, trash, 
drafts] remain.

What happened,  was I over quota size, or did something else happen ?
Shouldn't I have received a warning if it was over quota ?
I find it hard to believe that default practice is to snuff everything. 
How much account information is stored on the client side [me], and how 
much is stored on the server side [them] ?

Has anyone else on the list recently  lost  all their data from a 
Netscape Mail account ?

AIA
-- 

* green_man
** on **Thunderbird 0.4*