Some email replies from me come from the address to which the email was sent
and others come from my default address.

For example if I reply to a message that came to kozmo@thisaddress.com, the
reply comes from kozmo@defaultaddress.com. I can change it manually for each
reply but that's a pain and if I forget to it's a problem.

Not all messages behave this way. Some come from the correct "reply from"
address.  I can't figure out what the difference is for those that come from
the correct address.

I'm using OL2000 on XP, Internet Mail Only.

Any ideas what's happening?

thanks
Kozmo