choosing account to send email from

[Angela]

I am currently running Outlook 2000 with my primary
account being my exchange server. I also have 3 internet
mail accounts set up as separate services. I can recieve
mail from all accounts just fine, but have problems when I
try to send mail from anything other than my Exchange
Server account. I go into Services and then the Delivery
tab, and I move the internet accounts to the top of the
list - this sometimes sends email from the account at the
top, sometimes sends email from the account at the top "on
behalf of" my exchange server account and sometimes just
sends the mail from my exchange server account with no
reference to my internet account at all. Help?

Thanks in advance!
Angela