Application Settings Location (Horde)

Does anyone happen to know where the per user settings of Horde (formerly
Imp) reside? I can't find them anywhere in the home directory even though I
spent a very long time scanning every possible subdirectory. It is not mail
I am after, but rather the filters, among other settings. In the past I lost
all settings when the host upgraded Horde. I want to at least keep a copy of
the personalised settings. On this RedHat server, I tried looking under
/usr/share, but no luck either.

Thanks for any ideas you may have,

Roy