The entire error message would be helpful, but I suspect it is either e-mail
scanning, or Norton. Outlook Express does not like either. Start here.

Turn off e-mail scanning in your anti-virus program. It is a redundant layer
of protection that eats up CPUs, slows down sending and receiving, and
causes a multitude of problems such as time-outs, account setting changes
and has even been responsible for lose of messages. Your up-to-date A/V
program will continue to protect you sufficiently. For more, see:
http://www.oehelp.com/OETips.aspx#3

Note that for some AV programs, it may be necessary to uninstall the program
and reinstall in Custom Mode and opt out of e-mail scanning when the option
arises.

You aren't the only one with this problem. I've seen numerous references
to orangehome problems while searching on other subjects. Try this site
for help from people more familiar with your provider:

http://www.orangeproblems.co.uk/