In case of problems here's a list of all HORDE sites:
Jones, Biks, Vega, Louiz, Homebase.
And here's some other (older, IMP only) sites
(remember to select your own organisation when logging in...!):
dr. Jones, A-host, Homebase, Macvaerk.

Additionally, here's a few alternative webmail programs
(less secure, but might work better in some situations):
NOCC and AeroMail (jones.dk/homebase.dk).