Outlook 2000 takes 20 minutes to send 400kb zip file

[Steve]

I installed Outlook 2000 internet mail only on a new computer OS windows XP
media center. I also have a new DSL provider. I can send a 400kb zip file
using the providers e-mail service in 3 minutes (back to my own inbox). If I
use Outlook 2000 it could take as long as 20 Minutes for the e-mail with
attachment to arrive. Could I have misconfigured Outlook to work with the DSL
provider?

Any help would be appreciated!
Thanks