Possible solution number 1:
Switch to using Firefox as your browser. When you fill in your details, Firefox will ask you if you want to save the password. I've got several accounts on the same website, with different usernames and passwords. I only need to enter the first letter of a username and I'm offered an auto-complete option. As soon as I accept it the password is also automatically completed.
Possible solution number 2:
Use Outlook Express (or Windows Mail if you've got Vista) to send and receive your mail. If you've not already set up Outlook Express (or Windows Mail) to use with Orange, go to Tools > Accounts and click 'Add > Mail'. Just follow the prompts, ensuring that your incoming mail server is set to be a POP3 type (with the address entered as 'pop.orange.net') and that your outgoing mail server address is entered as smtp.orange.net
Chris