I only can give you a blind guess from here, but most providers are using different names for pop (receiving) and smtp (sending) mailservers. So maybe you should try to set the smtp-server's adress to "smtp.myprovider.com" instead of "pop3.myprovider.com".
Another issue could be that anonymous smtp is not allowed, so you have to authenticate before sending some mails. Usually this is done via "pop before smtp". Google for that, there are solutions to achieve this with Outlook Express (as far as I know only Outlook 2000 or greater supports this).
Good luck
Jake
Another issue could be that anonymous smtp is not allowed, so you have to authenticate before sending some mails. Usually this is done via "pop before smtp". Google for that, there are solutions to achieve this with Outlook Express (as far as I know only Outlook 2000 or greater supports this).
Good luck
Jake