Hmmm.
It's ages since I last used Outlook Express (and I've not used Spamfighter) but I'll try to give you a few pointers:
Firstly, I very much doubt that those dodgy emails are emanating from cisco.com. (Cisco is an extremely reputable company). What you're seeing in the 'From' field isn't the actual address that the mail came from; it's simply the 'reply address' that the spammer filled in there. (A spammer could send you an email with '
[email protected]' entered into that field, without that email ever having been anywhere near AB's servers).
So blocking mail from cisco.com probably isn't going to work (because that's not where it's coming from anyway). You could try to find out the actual address that the emails are coming from but, again, I suspect that might not work (because they're probably all coming from
different addresses). If you want to see where an email is actually coming from, follow the instructions here:
http://www.fraudaid.com/headers/outlookX.htm
(The example shown there appears to be a genuine email because the 'Received', 'From' and 'Return-Path' fields all have 'OdeonUK.com' in them. I doubt that you'd find such similarities in the spam emails that you've been receiving).
So you'll need to look for options, in either Spamfighter or Outlook Express, to block emails (or redirect them to your spam folder) based upon the 'reply address' (a.k.a 'return path') including 'cisco.com'. My problem then is that I'm not sure whether such an option exists!
The instructions for using Outlook Express's message rules are here:
http://www.simplehelp.net/2006/07/22/how-to-create-filters-in-outlook-express-6/
However that illustration doesn't show all of the options available (because you need to scroll down to see them), so I'm unsure as to whether it's possible to create a rule based upon the content of the return path. You'll need to take a look for yourself to see what's available to you.
You'll also need to explore Spamfighter's options for yourself, to see if it's possible to block emails by their return paths (rather than where they're really from).
If you really get stuck you might have to bite the bullet and get a new email account here:
http://www.gmx.co.uk
and use the 'Mail Collector' facility to get mail addressed to your old TalkTalk account forwarded to it. GMX's own spam filters might remove a lot of it for you anyway but, even if they don't, once you're certain that all of your contacts are using your new address you can completely ignore stuff that's going into the folder for our old address (or even disable mail collecting completely).
Oh well. it's taken me half an hour to compose all of that stuff, and I'm still not sure that it will help, but at least I tried ;-)