outgoing mail is not generally related to incoming - sometimes you will find ISPs use your incoming mail details username/pwd when connecting to their outgoing mail servers purely to authenticate the user.
Orange doesn't need to do this as it knows you are an orange customer because you are connecting to their broadband therefore your outgoing mail server will be something like mail.orange.co.uk or smtp.orange.co.uk
Your incoming mail details are not related to orange as they are handled by fnet and fsnet (like any other POP3 mail host) don't care how you connect to the internet. The only information you need for incoming mail collect is
your username, password and the POP3 mail server address.
You account name *might* be your email address or yourname.fsnet.co.uk
I read somewhere that if your email address is firstname.lastname@example.org
then your username is: myself.freeserve.co.uk
Somewhere else suggests : myself.freeserve.co.uk@fs
The POP3 server address will NOT have 'orange' in it at all, it is likely to be pop.freeserve.co.uk, pop.freeserve.com or pop.fsnet.net.
Can't be much more help really I'm afriad, call your friendly local Indian call centre is next I suggest